Leveling agents, as indispensable additives in the coating industry, play a crucial role. It can not only effectively reduce the surface tension of coatings, improve the leveling and uniformity of coatings, but also significantly improve the appearance quality and performance of coatings. Leveling agents mainly adjust the surface tension of coatings to promote the formation of a flat, smooth, and uniform coating film during the drying and film-forming process. It usually contains hydrophobic and hydrophilic groups, which can adsorb on the surface of the coating to form a molecular layer, thereby reducing surface tension and improving the flowability of the coating. In addition, leveling agents can improve the substrate wetting ability of coatings, reduce the possibility of spots and marks during brushing, increase coverage, and make film formation more natural.

There are various types of leveling agents, which are mainly divided into three categories based on their chemical structures: organosilicon, acrylic, and fluorocarbon. Organic silicon leveling agents have the ability to significantly reduce surface tension, good migration performance, and thermal stability. Among them, polydimethylsiloxane is the most commonly used silicone oil leveling agent, but its compatibility is poor and may affect the glossiness of the coating. Organic modified polydimethylsiloxane overcomes this drawback through modification, improving compatibility and performance. Acrylic leveling agents mainly achieve leveling effects by adjusting the uniformity of local surface tension inside the paint film. Including pure acrylic leveling agents and modified acrylic leveling agents, the latter such as fluorine modified acrylic leveling agents and phosphate modified acrylic leveling agents can significantly reduce the surface tension of coatings and have good substrate wetting properties. Fluorocarbon leveling agents are efficient but expensive, typically used when acrylic leveling agents and silicone leveling agents are difficult to function. It has high efficiency foam stability and interlayer adhesion, but it may also affect interlayer adhesion.

In the coating industry, the application of leveling agents is widely involved in solvent based coatings, water-soluble coatings, powder coatings, latex systems, and so on. Solvent based coating systems typically use acrylic leveling agents, while water-soluble coating systems often use organosilicon and fluorocarbon leveling agents. By selecting appropriate leveling agents, the construction performance of coatings and the decorative effect of the final coating can be significantly improved.