PI Series

What is PI coating?

PI coating refers to a high-performance coating that is applied to the surface of various substrates through chemical reactions or physical processes, using polyimide (PI) as the base material. Polyimide itself is a polymer compound with high thermal stability, high temperature resistance, corrosion resistance, excellent electrical properties, and good mechanical properties, widely used in aerospace, electronics, automotive, and other fields. Leveraging these excellent characteristics of polyimide, PI coating plays a significant role in many applications.

PI coatings typically exhibit high temperature resistance, corrosion resistance, electrical insulation, and high mechanical strength, effectively enhancing the durability, reliability, and performance of the coated substrates. They are widely used in various industries such as electronics, aerospace, automotive, and energy.

Characteristics of PI coating

Excellent high temperature resistance

Polyimide itself possesses high thermal stability, with a heat-resistant temperature range exceeding 300°C, and it can maintain its mechanical strength and chemical stability even at elevated temperatures. Therefore, PI coatings are highly suitable for use in high-temperature working environments, such as the protection of aerospace vehicles, electronic devices, and high-temperature equipment.

Excellent electrical insulation

The PI coating possesses excellent electrical insulation properties, effectively preventing current leakage and short circuits. This makes the PI coating play a crucial role in various fields such as electronic components, electrical equipment, and conductive circuit boards, providing long-term and stable electrical insulation protection.

Strong corrosion resistance

Polyimide exhibits excellent chemical resistance, capable of withstanding the erosion from acids, alkalis, solvents, and other chemical substances. Consequently, PI coatings find widespread application in various industrial sectors such as chemistry and energy, particularly in safeguarding equipment operating in highly corrosive environments.

Excellent mechanical properties

The PI coating not only exhibits high tensile strength and tear resistance, but also boasts excellent compression resistance, bending resistance, and friction resistance, enabling it to operate stably for extended periods in harsh environments.

Low friction coefficient and self-lubricating property

The low friction coefficient and self-lubricating properties of PI coatings make them highly suitable for applications that require resistance to friction and wear, such as machinery, electronic components, sliding contacts, and so on.

Good radiation resistance

PI coating exhibits strong resistance to ultraviolet rays and radiation, enabling it to withstand radiation effects for an extended period. Therefore, PI coating finds significant applications in aerospace, military, and other industries.

Environmental friendliness and non-toxicity

Polyimide and its coating materials generally exhibit good biocompatibility and are resistant to degradation in the environment. However, they do not release toxic substances during use, meeting modern environmental protection requirements.

Application areas of PI coating

PI coatings are widely used in multiple industries due to their high-temperature performance, chemical stability, electrical insulation, and mechanical properties. Below are some typical application areas of PI coatings:

Electronics and electrical industry

Circuit board protection

PI coatings are widely used for circuit board protection in electronic products, such as flexible printed circuits (FPC) and printed circuit boards (PCB). PI coatings effectively prevent circuits from moisture, oxidation, and other external environmental factors, ensuring long-term stable operation.

Battery protective film

Due to its excellent electrical insulation and high temperature resistance, PI coating is used as a protective film for battery components such as lithium batteries and capacitors, preventing internal short circuits, fires, or other hazards within the battery.

Protection of wires and electronic components

Many electronic components and wires require high temperature resistance, chemical corrosion resistance, insulation, and other properties. PI coatings can provide effective protection, enhancing the stability and service life of electronic components.

Aerospace field

Thermal protection coating

In aerospace vehicles, PI coatings can serve as thermal protection coatings on the outer surface of spacecraft, protecting them from high temperatures and radiation. PI coatings are capable of withstanding high temperatures, low temperatures, and radiation in various environments, ensuring the stable operation of spacecraft.

Avionics protection

Avionics equipment typically operates in harsh working environments. PI coatings can effectively protect the equipment from high temperatures, vibrations, radiation, and chemical corrosion, ensuring the safe operation of electronic systems.

automotive industry

Engine and exhaust system

Components such as automobile engines and exhaust systems often face high-temperature environments. PI coatings can protect these components from high-temperature damage and extend their service life.

High-temperature electrical components

Electrical components in automobiles, such as cables, batteries, and motors, are often exposed to high temperatures. PI coatings can provide electrical insulation and high-temperature resistance protection for these components, enhancing their reliability.

energy sector

Protection of high-temperature equipment

In the energy industry, such as oil, natural gas, and nuclear energy, equipment often needs to withstand various conditions such as high temperatures and corrosion. PI coatings are widely applied to the surfaces of pipelines, containers, valves, and other equipment in the energy sector, providing high-temperature resistance and corrosion protection.

Solar cell protective film

PI coatings are also widely used in solar cell modules, effectively protecting solar cells from stable operation under high temperatures and harsh environments, and improving photoelectric conversion efficiency.

Machinery and metal surface protection

Friction materials and sliding components

In machinery, PI coating is commonly used for surface treatment of friction components such as bearings, gears, and seals. PI coating not only provides self-lubricating properties but also reduces friction and wear, enhancing the durability of mechanical components.

Protection of metal substrates

PI coating can effectively prevent metal substrates from external corrosion, oxidation, wear, and other impacts, and is widely used for the protection of various tools and instruments.

other fields

medical equipment

PI coating has excellent biocompatibility, and therefore it is also used as a surface coating for medical devices, especially for medical instruments operating in high-temperature and high-pressure environments.

Flexible display protection

With the development of flexible electronic products, PI coatings have found applications in flexible displays and wearable devices, protecting the displays from external damage and environmental impacts.

Preparation and application process of PI coating

Preparation process of PI coating

The preparation of PI coating is typically carried out through techniques such as solution coating, spray coating, or dip coating. The specific process steps are as follows:

Solution coating method: Polyimide resin is dissolved in an organic solvent to form a solution of a certain concentration. Then, the PI solution is applied onto the surface of the substrate by coating, brushing, rolling, or other methods to form a uniform coating. After baking and curing, the coating forms a PI coating.

Spray coating method: The PI solution is sprayed onto the surface of the substrate to be coated using a spray gun, followed by curing. This method is suitable for substrates with large coating areas or complex shapes.

Dip coating method: Immerse the substrate in a PI resin solution to form a coating. This method is suitable for large-scale production and results in a uniform coating thickness.

The curing process of PI coating

The curing process is a crucial step in the formation of PI coatings, typically employing methods such as thermal curing or UV curing. During thermal curing, the PI coating undergoes a chemical reaction through heating, resulting in the formation of a stable polymer structure. The typical curing temperature ranges from 200°C to 300°C, and the curing time and temperature can be adjusted based on different coating thicknesses and coating requirements.

Market prospects of PI coating

With the advancement of technology and diversification of industrial demands, the application prospects of PI coatings are vast. Especially in aerospace, electronics, manufacturing, and new energy sectors, the demand for PI coatings continues to grow. Due to its excellent performance, PI coatings are expected to replace traditional coating materials in more high-tech fields and become one of the primary choices for coating materials in the future.

In summary, PI coatings, with their advantages such as high temperature resistance, corrosion resistance, and electrical insulation, have a very broad application prospect in various fields and will occupy an increasingly important position in high-performance coating materials in the future.