what is the raw material of polarizer film for lcd?
1. TAC membrane (cellulose triacetate membrane)
Under the catalysis of anhydrous acetic acid and sulfuric acid, the TAC membrane was prepared by tape casting after cellulose was acetic acid. It has good optical isotropy, high transparency, no image distortion, and good air and moisture permeability. The thickness of TAC film for polarizer production is 40 μ m、50 μ m、80 μ m； TAC film for polarized glasses is much thicker, such as 300 μ m。
TAC film manufacturers mainly include Fuji Film and Konica Company in Japan. China Lekai Film Group Co., Ltd., Wuxi Almay is the main manufacturer of TAC film for polarizer in Chinese Mainland.
what is the raw material of polarizer film for lcd?
2. PVA membrane (polyvinyl alcohol membrane)
PVA is produced by polymerization and saponification of vinyl acetate monomer synthesized from ethylene, acetic acid and oxygen. PVA film was prepared by tape casting. It has good optical transparency, good affinity with inorganic and organic dyes such as iodine, and high orientation when stretching. According to the information on the coating line, the degree of polymerization is usually 1700, 2400, 2600, 4000, etc. The higher the degree of polymerization, the higher the quality of polarizer that can be produced. Among them, 1700 is used for TN and STN polarizers, 2400 and 2600 are mainly for TFT, and 4000 is used for high durability polarizers.
At present, there are only two manufacturers of PVA film that can be used for the production of polarizers: Keli Co., Ltd. of Japan and Synthetic Chemical Co., Ltd. of Japan.
what is the raw material of polarizer film for lcd?
3. Protective film
The commonly used protective films for polarizers mainly include PE series protective films and PET series protective films.
One of the PE protective films is to apply a layer of adhesive on the PE (polyethylene) film with a thickness of 40-60 μ m. The other is to use co extrusion process to make a film composed of two layers of LDPE (low density polyethylene), EVA (vinyl alcohol) and other adhesive resins, with a thickness of 35~70 μ m。 LDPE as the substrate requires high transparency and no fish like stripes. High purity, etc. The main manufacturers of PE protective film (all in Japan) are Sanrong Chemical Research Co., Ltd., Keli Synthetic Film Co., Ltd., and Shuishui Chemical Industry Co., Ltd.
The structure of PET series protective film is similar to that of PE series, which is to coat a layer of adhesive on the sheet based PET film. Its price is generally 5 times that of PE series. In terms of film strength, scratch resistance, heat resistance, etc., PET series is obviously superior to PE series. The thickness of PET protective film is 25 μ m、38 μ m。 The requirements for the protective film are good appearance, low charge (anti-static), and balanced adhesion and easy peeling. The manufacturers of PET protective films include Ridong Electric Co., Ltd., Diren Dupont Film Co., Ltd., Fujimori Industry Co., Ltd. and Sanrong Chemical Research Co., Ltd.
what is the raw material of polarizer film for lcd?
4. Other supporting raw materials of polarizer
1. Release membrane
The release film is a kind of PET film with silicon surface treatment. The key technology to produce peel film is the formulation of silicon treatment agent on the surface of PET film, the selection of anti-static agent and the coating process of the treatment layer. At present, the main suppliers of peel film are Mitsubishi Chemical Polyester Film Co., Ltd., Diren DuPont Film Co., Ltd., Lintec Co., Ltd., Fujimori Industry Co., Ltd. and Toyo Metallizing Co., Ltd.
2. Reflective film
It is made by plating a layer of metal (metal with high light reflectivity, such as aluminum or silver) on the substrate (usually PET film). It is one of the materials used to produce reflective polarizers. Usually, such polarizers are used for display devices without backlight sources, and the display contents can only be identified by external light. Therefore, the requirements for the reflective film are that the reflectivity is uniform under high reflective efficiency, the coating is smooth and smooth, and there are no optical defects. It is known from the coating line that the reflective film is bonded with the polarizer through PSA, so the coating also needs to have a certain chemical corrosion resistance.
what is the raw material of polarizer film for lcd?
3. Semitransparent semireflective film
When a layer of metal (aluminum or silver) is coated on the substrate (usually PET film), the thickness of the coating directly affects its transmissivity and reflectivity, and the uniformity of the coating directly affects the uniformity of the final optical performance of the product. Therefore, the key to its production technology is to control the thickness and uniformity of the coating.
The polarizer made of semi transparent and semi reflective film is mainly designed to save energy. When the external light intensity is high, its reflective property can be used to identify the display content by reflecting external light; When the external light is not enough, enable the backlight, and use its transmission performance to let the backlight light pass through to identify the display content. The polarizer is widely used in mobile phones.
The latest technology is to use a specific semi reflective powder mixed in PSA, and apply this PSA on the surface of the polarizer. After the adhesive layer is dry, the semi reflective powder will naturally form a film, which also plays a role of semi transmission and semi reflection.
what is the raw material of polarizer film for lcd?
4. Phase difference membrane
When light passes through the liquid crystal layer, it will refract for many times, causing interference of light and affecting the display effect, especially when displaying images with rich colors or complex contents. The phase difference film is used for optical compensation to reduce or eliminate the color change caused by light interference.
According to different materials, the phase difference film can be divided into PC system, NORBORNEN system, liquid crystal coating type, zeona film, etc.
5. Broad vision cornea
This is an optical compensation film, which is used to realize optical compensation for the inclined liquid crystal in LCD by coating a layer of disk like liquid crystal compound on the substrate (usually TAC film), and orienting and fixing it. It is mainly used for TFT type LCD display, and its viewing angle can be expanded from the original 45 ° up and down, 90 ° left and right to 90 ° up and down, 120 ° left and right, without affecting the picture quality. It is widely used in LCD TV. According to online coating, the main manufacturers of Guangshi Cornea are Fuji Film Company, Nippon Petroleum Company and Sumitomo Chemical Company.