One of the functions of paint leveling agent: anti shrinkage cavity

There are many defects and shortcomings in the performance of coatings, which cannot be solved by simply using resins, pigments, and solvents. It is necessary to use some coating additives. Leveling agent is an indispensable one among these coating additives.

Shrinkage on the surface of the coating is a common problem, and leveling agents have become an indispensable part of the coating. The cause of shrinkage is due to the imbalance of surface tension. The substance that produces shrinkage pores has a lower surface tension than the coating film and is called a shrinkage agent. The surface tension of the coating must be higher than that of the shrinkage agent, which is called a shrinkage receptor. The reasons can be categorized as follows:

1. When several resins are mixed together, they can dissolve and even form a transparent coating when the solvent is properly mixed. But when the solvent is not properly mixed, some resins will precipitate during the solvent evaporation process, producing gel particles that become shrinkage agents.

2. External object pollution, floating objects with low surface energy in the air, and silicone particles in the drying oven falling onto the surface of the coating.

3. Low surface energy substances such as insoluble oils, silicone oils, and rubber particles are mixed in the coating.

4. The surface tension of the substrate is unbalanced, with some areas contaminated by low surface energy substances or the surface energy of the substrate being too low.

5. In coatings containing pigments or matte powders that have not been treated with wetting and dispersing agents, adding a substrate wetting agent will cause the substrate wetting agent to adsorb onto the exposed particle surface, forming a shrinkage agent. This problem often occurs in water-based matte paints.