How much do you know about wetting leveling agents for water-based coatings?

Wetting leveling agents can effectively reduce the surface tension of the system and significantly improve the construction effect of water-based paints. After adding a wetting leveling agent, the wetting and permeability of the paint to the substrate increase, and the leveling of the paint solution is improved. Sometimes it can also overcome the problem of shrinkage. More importantly, the leveling agent can solve common shrinkage problems, especially those caused by excessive use of defoamers. Excessive leveling agents can counteract the defoaming effect of defoamers, causing bubbles to form in the paint during construction. Some even have a significant foam stabilizing effect, so it is recommended to use wetting leveling agents with low foaming, good leveling, and low foam stability as much as possible. The combination of leveling agents and defoamers, including the selection of varieties and the control of dosage, is the focus of research on water-based paint formulations.

The ideal wetting leveling agent should include the following aspects: 

1. Effectively reducing the surface tension ability of the system, improving its wettability and permeability to the substrate; 

2. Has low foaming, unstable foaming, and low water sensitivity; 

3. Does not affect interlayer adhesion; 

4. Having a good balance of surface tension, it can improve substrate wetting without affecting leveling or causing defects due to excessive reduction of surface tension. 

The general dosage of wetting leveling agent is 0.1-1%, preferably controlled at around 0.3%. When the defoamer is excessive, in order to overcome shrinkage, the dosage of leveling agent may even exceed 1%. However, leveling agents are not required in the putty formula.