| 摘要 |
PROBLEM TO BE SOLVED: To develop a method for producing a polarizing film which can be used for a wet method while preventing fracture, impressions or the like by making use of spiral rubber rolls which hardly caused wrinkles or bending of a hydrophilic polymer film during transport. SOLUTION: In this method, a hydrophilic polymer film 1 is impregnated with a dichromatic substance and dipped and transported in a soln. 4 by plural guide rolls 2, 5, 6, 7 disposed outside and inside the bath while the film is stretched to obtain a polarizing film. In this process, a spiral rubber roll having spiral grooves symmetric with respect to the central part and having <=100 rubber hardness is used for at least one of the guide rolls 2, 5, 6, 7. Then a transparent protective layer is formed on one or both surfaces of the polarizing film. By this method, the swollen hydrophilic polymer film hardly suffers fracture or the like and the wet method can be used favorably. Production of wrinkles can be prevented by the spiral effect and a polarizing film of good quality can be efficiently produced in a high yield.
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