In coating formulas, many powder fillers are needed to improve the performance of various aspects of the coating and effectively reduce costs. However, since various fillers are inorganic powders, the particle size is relatively small, the specific surface area is large, and the force between particles is relatively strong. , easy to agglomerate, so it is necessary to use appropriate dispersants for different coating formulas to achieve the maximum effect.
1.Anionic paint dispersant
Most of them are composed of non-polar negatively charged lipophilic hydrocarbon chain parts and polar hydrophilic groups. The two groups are located at both ends of the molecule, forming an asymmetric hydrophilic and lipophilic molecular structure. Anionic dispersants have good compatibility and are widely used in water-based coatings and inks. For example, phosphate ester dispersant has a good viscosity reducing effect on various inorganic powders and is suitable for water and oil.
2.Cationic paint dispersant
Cationic paint dispersants have strong adsorption power and have good dispersion effects on carbon black, various iron oxides, and organic pigments. However, attention should be paid to the chemical reaction with the carboxyl groups in the base material, and attention should be paid not to use it at the same time with anionic dispersants.
3.Nonionic paint dispersant
It is non-ionized and uncharged in water, and its adsorption on the surface of pigments is relatively weak. It is mainly used in water-based paints. Used in conjunction with anionic dispersants as wetting agents or emulsifiers, it is widely used in water-based color pastes, water-based coatings and inks.
4.Amphoteric paint dispersant
It is a compound composed of anions and cations. Typical applications are phosphate ester salt type polymers. This type of polymer has a higher acid value, which may affect interlayer adhesion.
5.Electrically neutral coating dispersant
The sizes of the anionic and cationic organic groups in the molecule are basically equal. The entire molecule is neutral but polar, and is widely used in coatings.
6.Polymer paint hyperdispersant
Polymer dispersants are the most commonly used and have the best stability. Since one end of their anchoring groups is entangled with the resin and the other end is encapsulated with the pigment particles, their storage stability is relatively good.