How to choose the appropriate leveling agent for different water-based coating systems

The water-based coating system is divided into water-soluble system and latex system. Waterborne coatings are typically non Newtonian fluids with their characteristic viscosity and thixotropy. Due to changes in shear force during coating application, the thixotropy of the coating after coating is an important factor affecting leveling. Therefore, the shear force changes of water-based coatings in different systems are different. So how should we choose the appropriate leveling agent?

In water-soluble systems, it is necessary to strongly reduce the surface tension of the system. The most commonly used leveling agents are organosilicon leveling agents and fluorocarbon leveling agents, which have the same effect as their application in solvent based coating systems. Of course, if a truly smooth surface is required, acrylic leveling agents for water-based systems are necessary. 

For latex systems, the film-forming mechanism is completely different, and viscosity does not change with the evaporation of solvents. The use of leveling agents in the formula may improve the substrate wettability of the coating, while acrylic leveling agents can improve the smoothness of the paint film. However, the main flowability of the coating is mainly controlled and adjusted by adding rheological control agents.