The role of leveling agents in paint pigments

Leveling agents have many functions in paint pigments, mainly to reduce or eliminate surface defects on the coating, such as shrinkage, fisheye, orange peel, and pinholes. This is because the paint pigment leveling agent improves the leveling and wetting properties of the system before the paint film solidifies. The use of water-based leveling agents helps with air release, pigment dispersion, and improves the wettability of the substrate, achieving ideal leveling performance. Adding suitable water-based paint pigment leveling agents can significantly improve the film-forming performance. The main manifestations are:

1. Improve leveling performance and uniform coating performance.

2. Eliminate shrinkage and fisheye phenomenon.

3. Reduce the occurrence of orange peel and pinholes.

4. Improve substrate wetting.

5. Beneficial for air and solvent release.

6. Maintain or increase the recoating and adhesion properties of the substrate.

7. Helps with the dispersion of pigments.

Surface shrinkage is caused by the poor wetting of the substrate by the coating, and surface defects can also be caused by flow caused by surface tension. Pollutants with low surface tension, such as oil, silicone, grease, dust, glue, or overspray, as well as changes in composition or temperature gradients, can cause flow caused by surface tension. When the surface tension is different, the substance will flow from low surface tension to high surface tension.

The result of water-based leveling agent polymer determines its surface activity and is controlled to limit the compatibility of the product with the coating. The leveling agent will migrate towards the substrate coating and the air surface of the coating, thereby achieving the goal of forming a smooth coating with uniform surface tension on the coating surface. Orange peel usually occurs during the coating application process. Before the coating solidifies, it needs to be continuously leveled to eliminate the dry film of orange peel. This is because the evaporation and baking of solvents can cause changes in temperature, viscosity, and concentration. And these changes will cause changes in surface tension.