2, polyimide refers to the main chain containing an imide ring (-CO-N-CO-) of a class of polymers, which contains the structure of the phthalimide polymer is the most important. Polyimide as a special engineering materials, has been widely used in aviation, aerospace, microelectronics, nano, liquid crystal, separation membrane, laser and other fields. In the 1960s, countries are researching, developing and utilizing polyimide in the 21st century, one of the most promising engineering plastics.
3, use:
(1) film: polyimide is one of the earliest commodities, used for motor slot insulation and cable winding materials. The main products are DuPont Kapton, UBE Upilex series and Jongbuchi Apical. transparent polyimide film can be used as a soft solar cell substrate.
(2) Coatings: Used as insulating varnish for electromagnetic wires, or as high temperature resistant coatings.
(3) Advanced composite materials: used in space, aircraft and rocket components. It is one of the most high temperature resistant structural materials. For example, the United States of America's supersonic airliner program designed for the speed of 2,4M, the flight surface temperature of 177 ℃, the requirements of the service life of 60,000h, it is reported that has been determined that 50% of the structure of the material for the thermoplastic polyimide as a matrix resin carbon fiber reinforced composite materials, the amount of each aircraft is about 30t.
(4) Fiber: modulus of elasticity is second only to the carbon fiber as a High-temperature media and radioactive material filtering materials and bulletproof, fireproof fabrics.
(5) Foam: used as high temperature insulation materials.
(6) engineering plastics: thermosetting and thermoplastic, thermoplastic can be molded or injection molding or transfer molding. Mainly used for self-lubricating, sealing, insulation and structural materials. Guangcheng polyimide materials have begun to be used in compressor rotor, piston ring and special pump seals and other mechanical parts.
(7) adhesives: used as a high-temperature structural adhesive. Guangcheng polyimide adhesive as a high insulation potting material for electronic components has been produced.
(8) Separation membrane: used for a variety of gas pairs, such as hydrogen/nitrogen, nitrogen/oxygen, carbon dioxide/nitrogen or methane, etc., separation, from the air hydrocarbon raw material gas and alcohols in the removal of water. It can also be used as permeation evaporation membrane and ultrafiltration membrane. Because of the polyimide heat and organic solvent resistance, in the separation of organic gases and liquids has a particularly important significance.
(9) photoresist: there are negative and positive gel, resolution can reach submicron level. With pigments or dyes can be used for color filter film, can greatly simplify the process.
(10) in microelectronic devices: used as a dielectric layer for interlayer insulation, as a buffer layer can reduce stress, improve yield. As a protective layer can reduce the impact of the environment on the device, but also a-particle shielding, reduce or eliminate the device's soft error (softerror).
(11) liquid crystal display with the orientation of the alignment agent: polyimide in the TN-LCD, STN-LCD, TFT-LCD and the future of ferroelectric liquid crystal display of the orientation of the agent material are occupying a very important position.
(12) electric - optical materials: used as passive or active waveguide materials optical switching materials, etc., fluorine-containing polyimide in the range of communication wavelengths for the transparent, polyimide as a chromophore matrix can improve the stability of the material.
(13) moisture-sensitive materials: the principle of linear expansion using its hygroscopic can be used to produce humidity sensors.