Polarizing Element, Polarizing Plate, and Image Display Device Having Superior Durability and Heat Resistance and Preparing Method of Polarizing Element

摘要

The present invention is controlled to a durable zinc, boron and potassium content of the specific range of the polarizing element, in particular heat resistance is excellent polarizing element, a polarizing plate, a method of producing an image display device and the polarizing element. According to one embodiment of the invention, based on the weight of the polarizing element, the value of the zinc content (wt%) x boron content (wt%) / potassium content (% by weight) is 0.1 to 4.0, a boron content of 1.0 to 5.0 wt. %, and a potassium content of 0.3 to 2.0% by weight of the polarizing element, the polarizing plate containing the same, the image display device is provided. In addition, at least dyeing step, crosslinking step, in the polarizing element manufacturing method comprising a stretching step and a washing step, the dyeing step is iodine concentration of 0.05 to 0.2% by weight, potassium iodide concentration of 0.2 to 1.5 wt%, and the temperature 20 ~ 40 of the polyvinyl alcohol-based film in an aqueous solution haenghamyeo dyeing by dipping for 150 seconds to 300 seconds, The cross-linking step is haenghamyeo by immersion for the boron concentration 0.36 to 0.83 wt%, the concentration of potassium iodide is 4-7 wt% and a temperature of 15 ~ 60 of the cross-linked polyvinyl alcohol-based film in an aqueous solution for 30 seconds to 120 seconds, The zinc chloride, zinc iodide, zinc sulfate, zinc nitrate and nitric acid at least some kind of zinc salt is selected from the group consisting of the zinc at a concentration of 0.4 to 7.0 wt.% dye solution, an aqueous solution or a separate cross-linking at least a kind of a zinc salt aqueous solution treatment is included in the aqueous solution, the water washing step, the method for producing the polarizing element is provided for performing the immersion for 10 to 30 seconds is 25 ~ 30 temperature of the pure water in the polyvinyl alcohol-based film. Polarizing element, a polarizing plate and an image display device according to an embodiment of the present invention is the initial transmission rate and the orthogonal color is maintained, even under high temperature conditions permeability, durability, and heat resistance which exhibits excellent degree of polarization and the color is maintained. ;