What Is an Insulation Coating?
Insulation coatings are products that can produce an insulating film through a coating process.
There are various types of components contained, such as polyimide-based and epoxy resin-based. When an insulation coating is applied to an object to be coated, a highly insulating film is formed on the surface.
This insulating film makes it difficult for electricity to leak from the object, which is effective in preventing electric shock accidents due to electrical leakage. In addition to the common methods of spraying and dipping, electrostatic coating and electrodeposition coating are also widely used for insulation coatings, which provide excellent uniformity of film thickness.
Uses of Insulation Coatings
Insulation coatings are mainly used to insulate parts of products that are subject to high voltages, such as automobiles and home appliances. Coating with insulation coatings can increase resistance to voltage.
For example, since electric and hybrid vehicles use electricity as their power source, high voltage resistance is required for peripheral components, such as batteries and motors. Insufficient resistance to voltage can lead to electrical leakage, which in some cases can cause accidents such as fires. Insulation coating is an important process from the viewpoint of accident prevention.
Principle of Insulation Coatings
Insulation coatings are products that coat the surface of an object with a highly insulating insulator. Since insulators are materials that do not conduct electricity, they can be used for objects that require voltage resistance. There are three energy levels of electrons in an object: the valence band, the forbidden band, and the conduction band.
Of these three, the valence band, forbidden band, and conduction band are the highest energy levels, in that order. In general, electrons tend to be pinched from the valence band, which has the lowest energy. It is the electrons in the higher energy conduction band that have the greatest effect on conductivity. In conductors such as metals, some electrons exist in the conduction band. The free movement of electrons in the conduction band allows electricity to flow.
In insulators, on the other hand, electrons exist in the valence band but not in the conduction band. Electrons can be excited from a lower energy level to a higher level using the energy of light or heat.
Insulators have the property of requiring a great deal of energy to excite electrons from the valence band to the conduction band. This makes it practically impossible to excite electrons to the conduction band, resulting in a non-electrical state.
Other Information on Insulation Coatings
1. Application of Insulation Coatings on Printed Circuit Boards
In printed circuit boards, rust is a cause of failure earlier than the durability period. As a countermeasure, a moisture-proof insulation coating is used. This enables long-term use and stable operation. However, despite high demand, stable production is no longer possible due to various factors.
The biggest challenge is the long drying time. The drying time for moisture-proof insulation coatings is estimated to be 24 hours, making these coatings unsuitable for mass production. The poor productivity did not match the demand. As a countermeasure, we aimed to shorten the drying time by increasing the heating temperature, but this created other issues, such as additional equipment and higher running costs. This also placed a heavy burden on the product itself and was not feasible.
The fluorinated coating agent solved this problem and realized stable mass production. It boasts a high quick-drying performance and dries completely in 15 minutes. Compared to the conventional 24-hour drying time, the drying speed has been significantly shortened, resulting in improved production efficiency.
The ability to demonstrate performance at lower temperatures and lower film thicknesses than conventional coatings means that running costs can be expected to be reduced. The important performance of the film is also no problem in terms of flexibility, waterproofing, and heat resistance, as well as moisture-proof insulation.
2. The Future of Insulation Coatings
As electric vehicles become increasingly popular, their component shapes are becoming more complex, and technologies that enable more uniform coating are required. In the electrodeposition coating method, improvements are being made by changing the composition of the coating solution.