Coating dispersants refer to additives that can enhance and improve the dispersion properties of solid or liquid materials. When grinding solid coatings, a dispersant is added to help crush the particles and prevent the agglomeration of the crushed particles to keep the dispersion stable. Oily liquids that are insoluble in water can be dispersed into very small droplets under high shear stirring. After stopping stirring, they will quickly stratify under the action of interfacial tension. After adding a dispersant and stirring, a stable droplet can be formed. emulsion. Its main function is to reduce the interfacial tension between liquid-liquid and solid-liquid.
The composition of water-based paint In this part, there are film-forming substances, solvents (water), pigments and fillers, and additives. Among them, additives account for the smallest proportion in coatings, but they are also an important part and cannot be ignored.
Most of the pigments used in water-based coatings are mixed in the form of aggregates and agglomerates. If these particles cannot be dispersed into smaller particles or primary particles and form a stable dispersion, defects such as coarsening, flocculation, precipitation, floating color, and reduced tinting strength will occur.
Water-based paint additives-dispersants, their main functions are to reduce the time and energy required to complete the dispersion process, stabilize the dispersed pigment dispersion, modify the surface properties of pigment particles, and adjust the mobility of pigment particles. .
The dispersants used in water-based coatings must be water-soluble, and they are selectively adsorbed to the interface between the powder and water. Water-based industrial coatings are very different from ordinary architectural coatings. The viscosity is generally low. The viscosity is measured with a Tu-4 cup, which is generally 60-120 seconds. Therefore, the requirements for water-based industrial coatings on dispersants include good dispersion properties. Sticky, it also needs to have good anti-sinking properties.
Paint slurry dispersed The quality is not only related to the formulation of the material formula and the selection of raw materials, but also related to the dispersant. Therefore, in the paint production process, pigment dispersion is a very important production link, which is directly related to the storage, construction, appearance and performance of the paint film.
So the reasonable selection of dispersant is a very important production link. The types of dispersants include anionic, cationic, nonionic, amphoteric and polymeric.
Most dispersants achieve the purpose of dispersing pigments and fillers through the processes of wetting, grinding and dispersing, coupling and wrapping stability.
