What are the types of wetting and leveling agents

There are two common types of wetting and leveling agents: modified organosilicon and acrylic. Some polyoxyethylene based powder (APEO) compounds also have wetting and leveling effects. Due to the biological toxicity of APEO based powder compounds, they are not suitable for use. Other leveling agents include fluorinated surfactants and specialty lipid compounds, which are less commonly used. Organosilicon wetting leveling agent is a polyether modified compound of polydimethylsiloxane.

Modified organosilicon wetting leveling agent is a surfactant whose main function is to reduce the surface tension of the system. After the surface tension of the system is reduced, the flow leveling of the paint increases, and the wetting ability of the substrate is improved, which is conducive to overcoming the defects generated during the film formation process.

Acrylic leveling agents are not surfactants and do not affect the surface tension of the system. The mechanism of action of these leveling agents is to control the volatilization of solvents and water. During the drying process, they migrate to the surface of the coating, blocking it and preventing volatile components from evaporating too quickly, but they do not reduce the surface tension of the system themselves. Acrylic leveling agents are particularly effective in reducing the ripples on the surface of coatings, but they do not have anti shrinkage effect as they cannot reduce the surface tension. Acrylic leveling agents do not affect the recoating ability of coatings, and their dosage is larger than that of organic silicone leveling agents. Excessive use may cause the surface of the paint film to become sticky, making the coating more prone to dust adhesion.