POLARIZING FILM CONTAINING SYNDIOTACTIC POLYVINYLALCOHOL WITH DYE AND METHOD OF PRODUCING THE SAME

摘要

Provided are a method for preparing a syndiotactic poly(vinyl alcohol)-based polarizing film with a dye, its polarizing film which has a very excellent polarizing effect and is improved in the durability at a high temperature and a high humidity, and a liquid crystal display device containing the polarizing film. The method comprises the steps of firstly drawing a syndiotactic poly(vinyl alcohol) film; dyeing the drawn film in a dye solution containing 0.01-5.00 wt% of a dye at a temperature of 0-70 deg.C for 20 min or less; and secondly drawing the dyed film. Preferably the second drawing process is carried out in a boric acid aqueous solution, a formalin aqueous solution or their mixture of a concentration of 0.1-10.0 wt%. Preferably at least one of the first and second drawing processes is a band drawing or wet drawing performed with a constant drawing ratio at a temperature of 10-230 deg.C. Preferably the dye is a direct dye.