Leveling agents, as key additives in coatings, inks, and other fields, improve coating flatness by reducing surface tension. Leveling agents can be divided into three categories based on their chemical structure. Organosilicon, mainly modified with polyether silicone oil, reduces surface tension through the siloxane structure in the molecular chain segment, and has both wetting and flowability, but attention should be paid to compatibility with the system. Acrylic acid, such as fluorine modified polyacrylate solution, promotes uniform coating spreading by adjusting surface tension, suitable for high gloss coatings, and has little effect on recoating. Fluorocarbon polymers have extremely low surface tension and are suitable for low surface energy substrates (such as PP plastics), but the cost is relatively high.

Leveling agents adsorb at the interface between liquid and gas or solid through the synergistic effect of hydrophilic groups (such as hydroxyl and amino groups) and hydrophobic groups (such as carbon chains), reducing the surface tension of the system and promoting more uniform coating flow. For example, when organic silicon leveling agents migrate to the "paint film air interface", the total energy of the system decreases, and the leveling process occurs spontaneously.

However, when choosing and applying, we need to consider its compatibility and match it with the coating system to avoid shrinkage or delamination.

In addition, the construction temperature and curing energy (such as UV lamp power) also directly affect the leveling effect, and the type or amount of leveling agent should be adjusted according to the temperature requirements.