Antistatic agents can be divided into two types: external coating type and internal mixing type. External coating type antistatic agent refers to a type of antistatic agent used on the surface of polymer materials. The internal mixing type is when the polymer material is in a molten state and added to the internal mixing evenly.
Antistatic mechanism
The mechanism of the antistatic agent is mainly that the hydrophilic group of the antistatic agent increases the hygroscopicity of the film surface, absorbs moisture in the air, forms a thin water film, and plays the role of leaking electric charges.
External coating type: mainly to increase the ion concentration on the surface of the film, neutralize the positive charge with anions or neutralize the negative charge with cations to prevent the accumulation of charge.
Internal mixing type: In the process of polymer material molding, add a sufficient concentration of antistatic agent. When the mixture is in a molten state, the antistatic agent molecules form a directional arrangement at the interface between the resin and the air, and the lipophilic groups are embedded in the resin, and the lipophilic group is embedded in the resin. The water group extends to the outside of the resin. After the resin is cured, the hydrophilic groups on the antistatic agent molecules are all aligned toward the air side to form a monomolecular conductive layer. During the film making process, the antistatic agent molecules inside the material will continue to migrate to the surface, making the antistatic effect lasting. Since the above two types of antistatic agents achieve antistatic purposes by absorbing environmental moisture and reducing the surface resistivity of the material, they are highly dependent on environmental humidity. Therefore, the higher the environmental humidity, the stronger the water absorption of the antistatic agent molecules, and the more significant the antistatic performance. The higher the ambient temperature, the greater the saturated water content in the air, the stronger the movement of water vapor, the faster the migration of antistatic molecules in the film, and the better the antistatic effect.