Kapton®Polyimide PI films DuPont

Pi Polyimide Polyimide film (PolyimideFilm) is the best film insulating material in the world. It is made of pyromellitic dianhydride (PMDA) and diaminodiphenyl ether (ODA) in a strong polar solvent through polycondensation and parallel flow. Extended film formation followed by imidization

Vespel Sp-1 Pi Plastic Sheet Characteristic
It is yellow and transparent, with a relative density of 1.39 to 1.45. Polyimide film has excellent high and low temperature resistance, electrical insulation, adhesion, radiation resistance, and medium resistance. It can be used in the temperature range of -269 ° C to 280 ° C Long-term use within a short period of time can reach a high temperature of 400 ° C. The glass transition temperatures are 280°C (Upilex R), 385°C (Kapton) and above 500°C (Upilex S). The tensile strength is 200MPa at 20°C and greater than 100MPa at 200°C. It is especially suitable as the substrate of flexible printed circuit boards and insulating materials for various high-temperature-resistant motors and electrical appliances.

Polyimide Sheets Pi Classification
Polyimides are generally divided into two categories:
Thermoplastic polyimide, such as imide film, coating, fiber and polyimide for modern microelectronics, etc.
Thermosetting polyimide mainly includes bismaleimide (BMI) type and monomer reactant polymerization (PMR) type polyimide and their respective modified products. BMI is easy to process but relatively brittle.

Film classification
Including two types of phenylene polyimide film and biphenyl polyimide film. The former is a product of DuPont in the United States, with a trade name of Kapton, which is made from pyromellitic dianhydride and diphenyl ether diamine. The latter is produced by Japan's Ube Industries, with a trade name of Upilex, which is made from biphenyltetracarboxylic dianhydride and diphenyl ether diamine (R type) or m-phenylenediamine (S type).

Advantages of China Vespel Sp-1 Pi Plastic Sheet

(1) Excellent heat resistance. The decomposition temperature of polyimide generally exceeds 500°C, sometimes even higher, and it is one of the most thermally stable species among known organic polymers, mainly because the molecular chain contains a large number of aromatic rings.

(2) Excellent mechanical properties. The tensile strength of the unreinforced matrix material is above 100MPa. The tensile strength of Kapton film prepared with homoanhydride is 170MPa, while biphenyl polyimide (Upilex S) can reach 400MPa. The elastic modulus of polyimide fiber can reach 500MPa, second only to carbon fiber.

(3) Good chemical stability and heat and humidity resistance. Polyimide materials are generally insoluble in organic solvents, and are resistant to corrosion and hydrolysis. Varieties with different structures can be obtained by changing the molecular design. Some varieties can withstand boiling at 120°C for 500 hours at 2 atmospheres.

(4) Good radiation resistance. The strength of polyimide film remains 86% after 5×109rad dose radiation; some polyimide fibers maintain 90% of their strength after 1×1010rad fast electron radiation.

(5) Good dielectric properties. The dielectric constant is less than 3.5. If fluorine atoms are introduced into the molecular chain, the dielectric constant can be reduced to about 2.5, the dielectric loss is 10, the dielectric strength is 100 to 300kV/mm, and the volume resistance is 1015-17Ω·cm. Therefore, the synthesis of fluorine-containing polyimide materials is a hot research field.

The above properties are stable over a wide range of temperature and frequency. In addition, polyimide also has the characteristics of low temperature resistance, low expansion coefficient, flame retardancy and good biocompatibility. Polyimide can be widely used in many fields due to its excellent comprehensive properties and the diversity of synthetic chemistry.

Vespel SP-1 Application industry

The polyimide film known as "golden film" has excellent performance, it is widely used in space technology, F, H class motors, insulation of electrical appliances, FPC (flexible printed circuit board), PTC electric heating film, TAB ( Pressure-sensitive tape substrate), aerospace, aviation, computer, electromagnetic wire, transformer, audio, mobile phone, computer, smelting, mining, electronic components industry, automobile, transportation, atomic energy industry and other electronic and electrical industries.

Vespel SP-21 Application field

(1) Film: It is one of the earliest products of polyimide, which is used for slot insulation of motors and cable wrapping materials. The main products are DuPont's Kapton, Japan's Ube Industries' Upilex series and Zhongyuan's Apical. Transparent polyimide film can be used as a flexible solar cell backplane;

(2) Coating: used as insulating varnish for electromagnetic wire, or used as high temperature resistant coating;

(3) Matrix resin of advanced composite materials: used in aerospace, aerospace vehicle structure or functional components, and parts of rockets, missiles, etc., is one of the most high temperature resistant structural materials;

(4) Fiber: The elastic modulus of polyimide fiber is second only to carbon fiber, and it can be used as a filter material for high-temperature media and radioactive substances and bulletproof and fireproof fabrics;

(5) foam plastic: it can be used as high temperature resistant heat insulation material;

(6) Engineering plastics: thermosetting and thermoplastic, can be molded or injection molding or transfer molding (RTM), mainly used for self-lubricating, sealing, insulation and structural materials. In addition, polyimide can also be used as adhesives, separation films, photoresists, dielectric buffer layers, liquid crystal alignment agents, electro-optic materials, etc. in high temperature environments.