Application and selection of leveling agents

For a determined formula system, the appropriate type of leveling agent should be selected based on the properties of the formula and the desired performance of the leveling agent.

When determining the water-based formula, it is common to choose a wetting agent first, followed by a leveling agent. Some additives can act as both wetting agents and leveling agents. 2. Do not use a large amount of wetting agents that strongly reduce surface tension, as long as they are sufficient, as they will prolong the leveling agent.

2. Solvent based coating systems typically use acrylic leveling agents in primer and intermediate coat formulations. If degassing and low material wettability are required, it is advisable to choose medium or high molecular weight acrylic leveling agents. In primers such as fluorine modified acrylic leveling agents and phosphate modified acrylic leveling agents, if organic silicon leveling agents and fluorine modified acrylic leveling agents have side effects such as foam stabilization and affecting interlayer adhesion, phosphate modified acrylic leveling agents should be used. In the formulation of topcoat and transparent paint, the requirements for the appearance of the paint film are relatively high. Generally, low-molecular-weight acrylic leveling agents can be used to achieve good leveling performance and prevent fogging in the paint film.

3. The leveling process of powder coating system is divided into two stages. The stage is the melting of powder particles, and in the second stage, the powder particles melt and flow into a smooth paint film. Powder coatings do not contain solvents and do not generate surface tension gradients during film formation. Leveling is more related to low material wetting. Powder coatings often use acrylic leveling agents. If the leveling agent is in liquid form, it usually needs to be pre made into a masterbatch before use.

4. The water-based coating system is divided into water-soluble system and latex system. In water-soluble systems, it is necessary to strongly reduce the surface tension of the system. Commonly used leveling agents are organosilicon leveling agents and fluorocarbon leveling agents, which play the same role 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.