POLARIZING FILM AND MANUFACTURING METHOD FOR THE SAME

摘要

A polarizing film and a manufacturing method thereof are provided to increase durability with predetermined polarization efficiency and transmittance by lowering the moisture absorptivity of the polarizing film. A polarizing film is produced by dyeing a polyvinyl alcohol film with dichromatic dyes before, during, or after uniaxially stretching the polyvinyl alcohol film and then sticking the dyed polyvinyl alcohol film in a cross-linking agent aqueous solution. The polarizing film left at 25 degrees centigrade and 65RH(Relative Humidity) for 24 hours has the moisture absorptivity of 0.5 to 5.7% defined by the weight ratio of moisture measured at 50°C by a vacuum drying method. A cross-linking agent is at least one selected from BTCA(Butanetetracarboxylic Acid), polycarboxylic acid like citric acid, cyclic urea compounds such as DMDHEU(Dimethylol Dihydroxyethylene Urea), and aldehyde compounds such as formaldehyde.