Preparation method and application of polyvinyl alcohol film for producing polarizer

Abstract

The invention discloses a preparation method of a polyvinyl alcohol film for producing a polarizer. The method is characterized by comprising the following steps: with polyvinyl alcohol as a solute and water as a solvent, preparing a polyvinyl alcohol solution; adding iodide ions to the polyvinyl alcohol solution; evenly stirring to obtain an iodine polyvinyl alcohol solution; and preparing the polyvinyl alcohol film from the iodine-ion-containing polyvinyl alcohol solution by a tape casting method or a strip coating method. According to the preparation method, iodine is added to the polyvinyl alcohol solution, so that the iodide ions can be uniformly distributed into a polyvinyl alcohol structure in a mechanical mixing manner. The preparation method has a better effect than an existing diffusion method. The produced polarizer has a better polarizing effect.

Description

technical field [0001] The invention relates to a preparation method of a polyvinyl alcohol film, in particular to a production method of a polyvinyl alcohol film used for polarizer production and its application in preparing polarizers. Background technique [0002] The polarizer can polarize natural light, and when it is combined with liquid crystal, it becomes a component with imaging function, which is a key part of the liquid crystal display. [0003] The current production method of the polarizer is: adding polyvinyl alcohol to quantitative water, dissolving under high temperature and high pressure and adding a plasticizer, and obtaining a polyvinyl alcohol film by casting method, drying and heat treatment. Then the polyvinyl alcohol film is washed and expanded, soaked in iodine / potassium iodide solution for coloring, stretched to a certain multiple, shaped with boric acid solution, and bonded with the protective film to form a polarizer. [0004] In the above-mention...

AI Technical Summary

Problems solved by technology

Specifically: 1. During the production process, the temperature of the solution is high and the diffusion effect is good, but if the temperature is too high, the polyvinyl alcohol film will dissolve and reduce its mechanical properties, which is not conducive to the control of the effect of the subsequent stretching process; 2. Polyvinyl alcohol In the production process of the film, high temperature processes such as drying and heat treatment are required. The hydroxyl groups in the molecular structure, especially the 1,2-diol bond units, are prone to hydrogen bonds. At the same time, high temperature heating also improves the crystallinity of polyvinyl alcohol molecules. , these all hinder the diffusion of iodide ions in the film; 3. During the diffusion process of iodide ions, affected by the structure of polyvinyl alcohol film, the diffusion speed is not completely consistent, resulting in uneven distribution of iodide ions, resulting in the polarization of each point on the film There are certain fluctuations

All of the above factors will adversely affect the polarizing performance of the product