Polyimide (PI) is a new type of high temperature resistant thermosetting engineering plastic, because it can maintain high physical and mechanical properties in a wide range of temperature of -269～400℃, and can be in the air of -240～260℃. Long-term use, and has excellent electrical insulation, wear resistance, high temperature radiation resistance and physical and mechanical properties, so it is widely used in electromechanical, electronic and electrical, instrumentation, petrochemical, metering and other fields, and has become a global rocket, aerospace, etc. One of the indispensable materials in the field of cutting-edge technology.

Since the first industrial production of polyimide by DuPont in the United States, Japanese companies such as Toray DuPont, Ube Industries, Zhongyuan Chemical and Mitsubishi Chemical have successively developed and produced polyimide resins and films. The former Soviet Union also More than 20 varieties of grades have been developed successively. In addition, the Japanese polyimide company also has a set of 400 tons/year thermosetting bismaleimide equipment, and the original French Rhone Planck company can also produce polyamideimide resin.

From the perspective of demand, the main consumption regions of polyimide are concentrated in the United States, Japan and Western Europe. According to statistics, in 2000, the demand for polyimide in the United States, Japan and Western Europe was 10,000 tons, 3,000 tons and 3,200 tons respectively, which were mainly used for the production of molded parts, enameled wire coatings and films.

In recent years, major foreign companies have been expanding the production scale of polyimide, developing new varieties and new grades, seeking ways to further reduce costs, and through the development of thermoplastic polyimides and the use of blending modification methods, Further improve the processing properties of polyimide. For example, blending modification of polyimide and bismaleimide, bismaleimide and epoxy resin can improve the processability and other properties of the material.

At present, polyimide HF composite film is mainly used to manufacture H-class thin film wires and aviation wires. Among them, H-class thin film wires are mainly used in the motors of electric locomotives and diesel locomotives, and aviation wires are mainly used in aircraft power lines and instrument lines. Polyetherimide plastic products have begun to be applied not only in high-tech fields such as rockets and satellites, but also in automobiles, office equipment, home appliances, mechanical seal parts and other fields. In addition, with the development of the electronics industry in recent years, the amount of flexible polyimide clad copper foil is also increasing, and the composite material made of bismaleimide and epoxy resin also has a broad field in the aerospace field. Application prospects.