Dispersant is an amphiphilic chemical that can increase the compatibility of oily and aqueous components in the same system. Dispersants are additives that can enhance and improve the dispersibility of solid or liquid materials. With the development of today’s society, water-based coatings are becoming the mainstream of the coating family. There are many factors that affect a good water-based coating. Among the components of the coating, there are film-forming substances, solvents (water), pigments and fillers, and additives. Among them, additives account for a small proportion of the coating, but it is also a very important part and cannot be ignored.
The following is a brief introduction to water-based dispersants for water-based coatings.

The principle of dispersants: Most dispersants achieve the purpose of dispersing pigments and fillers through the process of wetting, grinding and dispersion, coupling and encapsulation stabilization. In water-based coatings, due to cost control reasons, more expensive dispersants cannot be used. Most of the wetting and dispersing agents used in the market now are anionic and non-ionic. Their principle is that they have low surface tension, quickly wet the pigment particles, and then form a semi-flocculated (or controlled flocculated) dispersion through high shear force, such as dispersers and grinding machines. If the viscosity of the water-based paint is relatively high at this time, there will be no pigment coarsening and serious flocculation, but if the viscosity is not well controlled, problems will occur over time; some use coupling agents as dispersants to couple two different substances together through their hydrophilic groups and sulfur water groups. Like a bridge, the advantages of doing so are: good comprehensive performance, dispersion, low dosage, and increased adhesion of water-based paint, but the disadvantage is that it is not a deflocculating group, and it is not suitable for water-based paints with high color development requirements. Through research and practice, it is recommended to use a deflocculating dispersant in water-based paints. Because the advantages of doing so are: good color development of pigments and fillers, high brightness, and good gloss. However, in pure emulsion systems, we recommend the use of dispersants that enhance charge repulsion. Such as electrically neutral amine salts and polycarboxylates.

Water-based dispersants can be divided into: ① anionic, ② cationic, ③ non-ionic, ④ amphoteric, ⑤ neutral type, ⑥ polymer (including high, medium and low molecular weight) super dispersants.