LCD polarizing film production of the basic method

Currently polarizing film production techniques to extend PVA film technology division, there are dry and wet hair into two categories; PVA membrane staining method to divide, and iodine staining dye-based two categories.

Dry polarizer technology is the production of a PVA film is at a certain temperature and humidity conditions of the steam environment for extended process method, the early use of this process for the purpose of the process is the production efficiency can be improved, compared with width Big PVA film production which is not often broken membranes. However, the limitations of this process is that during the extended PVA film uniformity is limited, so the original film to form a polarizing composite film tension, color uniformity and durability, not easy stability, and therefore the production process in the actual application of the more less. Wet process polarizer technology is the PVA film is a dyed liquid ratio, stretching process method. This process approach is limited in the early PVA film extending in the liquid stability control difficult, so using this process the PVA film processing film is easily broken, and the limited width of the PVA film. But with the improvement of industrial control technology, the limitations of these wet processing technology has been greatly improved, from the late 1990s onwards, Japanese companies have generally adopted Polaroid width 1330 mm TAC film with wet process for polarizing film production. Especially due to large-size TFT-LCD products, massive popularity, to improve the utilization of Polaroid products to 1330 mm width as the basic production polarizer LCD polarizing film has become the basic method of production.
Polaroid production processes in the dyeing method iodine staining and dye staining two processes. Iodine staining refers to the polarizer dyeing, stretching process, the use of iodine and potassium iodide as two isotropic medium the PVA film generates polarized polarizing properties. The advantage of this dyeing method is relatively easy to obtain a high of 99.9% or more than 42% degree of polarization and the polarization properties of a high transmittance. Therefore, the polarization in the early or need high polarizing materials, the high transmission characteristics of polarizing material products are used mostly iodine dyeing processing. But this process is because of the inadequacy low temperature lcd display of the molecular structure of iodine in hot and humid conditions easy damage, so using iodine staining process to produce polarizing film durability is poor, generally only meet the dry temperature: 80 ℃ × 500HR, humidity: 60 ℃ × 90% RH × 500HR use the following conditions apply.
But with the expansion of the scope of LCD products using the polarized product humid working conditions become more demanding requirements has appeared in 100 ℃ and 90% RH polarizer work under conditions of demand for this kind of work conditions require, iodine staining process on the powerless. To meet the requirements of this technique, first by Nippon Kayaku Co., invented a dye polarizing film for production, by a subsidiary of Nippon Kayaku, Japan Bora lines produced high durability of the dye polarizing sheet product. The use of two isotropic dye dyeing Polaroid Polaroid produced products meet the highest dry temperature: 105 ℃ × 500HR, heat:lcd module 90 ℃ × 95% RH × 500HR following working conditions requirements. However, this process for the production of polarizing film products are generally low degree of polarization and the transmission, the polarization degree is generally not more than 90% transmittance of not more than 40%, and expensive.