Cook Islands What are the ink defoamer for paints(1)

water-based

Dispersant is a kind of interfacial active agent that has both opposite properties of lipophilicity and hydrophilicity within the molecule. It can uniformly disperse solid and liquid particles of inorganic and organic pigments that are difficult to dissolve in liquids, while also preventing particle sedimentation and condensation, forming amphiphilic reagents required for stable suspensions

Cook Islands Selection of antifoaming agents for different applications:

Flat coating

Features: Low viscosity, low defoaming pressure

Recommendation: Mineral oils or mineral oil modified polyethers

Elastic coating

Features: High viscosity, high ink defoamer pressure

coating

Action mechanism of polysiloxane defoamer
The representative defoaming mechanisms of polysiloxane mainly include "bridging spreading" mechanism, "bridging dehumidifying" mechanism, and "spreading liquid entrainment" mechanism. The "bridging spreading" mechanism mainly starts from the basic point of "polysiloxane has a relatively low tension and is easy to spread on the liquid film." It emphasizes that defoamer droplets are prone to deformation, but this theory cannot explain the defoaming differences between individual polysiloxanes and mixtures of polysiloxanes and solid ions as defoamers. The "bridging dehumidification" mechanism is mainly based on the hydrophobicity of polysiloxanes themselves, but the defoaming effect of polysiloxanes with high viscosity cannot be well explained. The "spreading liquid entrainment" mechanism cannot be confirmed because some facts indicate that polysiloxanes sometimes do not spread on the surface of the foam film, but can also break the foam.

Recommendation: Polyether modified silicone

Defoaming mechanism of hydrophobic solid particles
Hydrophobic solid particles in the foam system will first attract the hydrophobic end of the surfactant, making the hydrophobic solid particles become hydrophilic, thus reducing the concentration of surfactant in the foam film and promoting the foam to burst. This defoaming mechanism cannot explain the action mechanism of other defoaming agents, which is too one-sided. [4] Other reasons for the bursting of foam are the impact caused by the expansion of defoamer, the solubilization of surfactant and the collapse of electrolyte, and the bursting of electric double layer on the liquid film surface. [4] It can be seen from the above defoaming mechanisms that each defoamer has different emphasis on different foam systems, but defoaming is achieved by destroying the stability factors of foam

Surface coating and film covering adhesive

Recommendation: Polyethers, which can effectively prevent surface defects and have a small impact on gloss

Water in Water Colorful

agent

Features: More surfactants, stable foam

Cook Islands Recommendation: Use polyethers or mineral oil to modify polyethers

Precautions for use of paint ink defoamer:

Before use, stir thoroughly and mix evenly; Adding the paint while stirring; Before use, it is generally not diluted with water; The dosage should be appropriate. Excessive dosage can cause shrinkage, edge shrinkage, poor brushing performance, and other problems; Too little dosage leads to poor defoaming effect; Add it in two stages, namely, add it in the grinding stage and the paint mixing stage, generally accounting for half of the total amount each time. Use defoaming agents with good foam suppression effect in the grinding stage, and use defoaming agents with good foam breaking effect in the paint mixing stage