Polyimide (PI) is a high-temperature polymers, at 550 ℃ can maintain the main physical properties of
short-term, long-term use at nearly 330 ℃. In the high-temperature engineering plastics, it is one of the
most valuable species. It has excellent size and oxidation stability, chemical resistance and radiation
resistance, and good toughness and flexibility. It can be widely used in aviation / aerospace, electrical /
electronics, motorcycles, automobiles, precision machinery and automated office machinery and other
Since polyimide has a very stable molecule aromatic heterocyclic structure to reflect the other polymer
materials can not match the excellent performance: temperature and low temperature resistance,
biphenyl dianhydride and p-phenylenediamine synthetic PI, the thermal decomposition temperature of
up to 600 ℃, is one of the
higher thermal stability of the polymer species to date. In such a temperature, short time can basically
maintain the original physical properties. Long-term use in the following 333 ℃, addition still does not
at -269 ℃ embrittlement; high mechanical strength, tensile strength pyromellitic type PI film can reach
170MPa, and biphenyl type can reach 400MPa, as the temperature increases , little change;
resistance to radiation is good; excellent dielectric properties; chemical stability, acid and alkali very
stable; in addition, PI creep resistance and strong, excellent tribological properties.
2003 polyimide global consumption of about 35,000 tons, about 50 more than the major manufacturers.
Currently, the consumption of the United States, Western Europe and Japan have been more than 20,000
tons / year, of which the United States is 1.3 million tons / year, is expected in 2004, the consumption of the
United States, Western Europe and Japan will reach 27,000 tons / year. The United States has 14, 11 in
Western Europe, Japan has 13 production plants produce PI. In addition, Russia, China, India, Korea,
Malaysia and Taiwan have a small amount of production and consumption of PI. Polyetherimide (Ulterm)
PI about 70 percent of US demand, because of its good performance and processing characteristics,
there is a tendency with a polyether sulfone, polyphenylene sulfide, and other aromatic PI competition.
It expects global demand for the next few years will average polyimide rate of about 10% annually.
Almost simultaneously with the world of research and development began to gather imide, research
and development pattern has been basically formed, PI has developed several varieties, such as pyromellitic,
partial anhydride type, biphenyl dianhydride type, bisphenol A dianhydride type, single ether anhydride type,
ketone anhydride type, etc., and preliminary applications. Now there are nearly 20 manufacturers, production
capacity has more than 800 tons / year. 2002 PI film market strength, production capacity has reached 750
tons / year, in 2003 six production plants will add a total capacity of 400 tons / year, the manufacturer expanded
to 26. 4 film export manufacturers, plus copper clad exports, the national export volume of nearly 70 tons / year.
2001 domestic production of about 400 tons. Nanjing, the first special engineering plastics Plastic Products
Co., Ltd. is a major production of domestic polyimide profiles and products manufacturers, has established
long-term stable cooperative relations major medium-sized enterprises, major research institutions, various
Polyimide our main defense industry development with the rapid development, research and application in
some areas has reached the world level. The gap with foreign advanced countries, mainly in small-scale
production plant is currently the largest of 100 tons / year, developed countries are basically kiloton scale;
poor quality of our products, unstable performance, affect the application; product refinement not enough,
fewer species, mainly in poly pyromellitic polyimide film, etc, the application field is mainly films and molded
plastic, and a wide variety of foreign products, such as films, molded parts, coatings, adhesives , enamel,
foam and fiber. China should in the development of existing varieties while developing polyetherimide,
poly biphthalic polyimide, thermoplastic polyimide and bismaleimide resins and other major varieties of
a larger amount.