| 摘要 |
PROBLEM TO BE SOLVED: To enable to obtain a polarized film having a high contrast and useful for outdoor liquid crystal display devices, low power consumption liquid crystal display devices, etc., by orienting a polyvinyl alcohol resin film in a specific ratio in an aqueous boric acid solution. SOLUTION: This method for producing a polarized film comprises monoaxially orienting (A) a polyvinyl alcohol resin film (e.g. the film having a resin polymerization degree of 1,000-10,000) in an orientation ratio of 4-8 times e.g. by a dry method, allowing the film to adsorb (B1 ) iodine or (B2 ) a dichroic dye, immersing the film in (C) an aqueous boric acid solution [e.g. a solution containing 2-18 pts.wt. of boric acid in 100 pts.wt. of water] e.g. in conditions comprising a temperature of >=50 deg.C and an immersion time of 100-1,200 sec and simultaneously again orienting the film in a ratio of 1.1-1.8 times. |
