替换城市 Principle and influencing factors of special paint defoamer agents for paints(4)

viscosity-reducing

leveling

agent

When the paint is baked at high temperature at room temperature, its viscosity will drop at the beginning, and bubbles can move to the surface. However, because of the volatilization of solvent, the curing of paint, and the increase of surface viscosity, the foam will become more stable and retain on the surface, resulting in shrinkage and pinholes. Therefore, the baking temperature, fixing speed, and solvent volatilization rate also have an impact on the effect of defoamer.

Solid content, viscosity, elasticity of paint

high

Leveling principle
The compatibility of acrylic leveling agents is an important indicator of their ability to control the surface state of the coating film. The compatibility is too good to dissolve in the coating film, which will not form a new interface on the surface of the coating film and provide no leveling effect; Due to poor compatibility, it is impossible to uniformly distribute on the surface of the coating film, which can gather together and easily cause shrinkage defects. It can reduce the gloss of the coating film and produce adverse side effects such as fog and shadow. Only with ideal controlled compatibility can a new interfacial layer be formed on the surface of the coating film, playing a leveling role

替换城市  High solid thick film, high viscosity and high elasticity coatings are very difficult to defoamer. In these coatings, defoamer diffusion is difficult, microbubbles become larger slowly, foam migration ability decreases, foam viscoelasticity is large and many other adverse defoamer factors. Foam in these coatings is very difficult to eliminate, so defoamer and defoamer should be used together.