What Is a Moisture-Proof Coating Agent?
Moisture-proof coating agents are used to apply a protective film on surfaces, enhancing their resistance to moisture. They are commonly used on printed circuit boards to create a moisture-proof protective layer.
Uses of Moisture-Proof Coating Agents
Moisture-proof coating agents protect electrical and electronic equipment from moisture, corrosion, and oxidation. They are crucial in preventing malfunctions and failures caused by short circuits, wire breaks, and current leakage. Conformal coating, a method of applying these agents uniformly, shields substrates and components from airborne contaminants.
Fluorinated agents are often preferred for their high moisture resistance, ease of application, and room-temperature drying capabilities.
Principle of Moisture-Proof Coating Agents
These agents work by creating a surface with low tension and repelling water, which has higher surface tension. This causes water to form droplets on the coated surface, ensuring waterproofing. Fluorine-based agents, with their stable C-F bonds, further reduce surface tension, enhancing moisture repellence.
Types of Moisture-Proof Coating Agents
There are several types of moisture-proof coating agents, each with unique properties and applications.
Acrylic and Urethane Types
Used for circuit boards and automotive ECU substrates, acrylic and urethane agents provide effective protection but require thicker films and careful handling due to flammability.
Silicone-Based
Silicone-based agents form flexible, rubber-like films and are versatile, but they can diffuse low-molecular-weight compounds, potentially affecting contact integrity.
Olefin-Based
Olefin-based agents also create rubber-like films with high moisture resistance. Similar to silicone-based agents, they contain organic solvents and necessitate careful handling.
Fluorine-Based
Fluorine-based agents are notable for their thin-film application, high resistance to moisture and acids, and lightweight impact on substrates. They are effective against environmental factors like lithium battery electrolyte exposure and hydrogen sulfide.