Selection of defoamers for thick water-based coatings

The focus of thick water-based coatings is not on defoamers, but on defoaming. Due to the high viscosity of thick water-based coatings themselves, bubbles in the thick water-based coating system cannot appear on the surface. Therefore, when choosing defoamers, it is necessary to remove the bubbles in the system to achieve the defoaming effect and not affect the coating.

Mineral oil defoamers are the preferred choice. Why is mineral oil defoamer the preferred choice? Because its main reason is the high viscosity of thick water-based coatings, mineral oil has poor dispersibility in the system and may not function well, even forming floating, which affects the entire latex paint system.

If a low viscosity defoamer is added to a thick water-based coating, it will inevitably cause immiscibility and affect the color and glossiness of the coating. Therefore, when choosing a defoamer, it is important to choose a mineral oil defoamer with a high viscosity in order to dissolve well and remove bubbles from the system.