The influence of the dispersion of pigment on the paint
In the use of coatings, people often encounter problems of flocculation, lack of color or transparency, poor rheology, or poor stability, all of which are closely related to the lack of adequate dispersion of the pigment.
In pure theory, “ well dispersed ” it means that each pigment particle in the system is completely dissolved in the flocculation state, that is, each pigment particle is wrapped by a thin layer of lacquer or solvent. In fact, however, it is difficult to achieve. Then, what is the effect of pigment dispersity on the properties of coatings?
1, gloss: if the pigment is best dispersed, this can directly improve the gloss. In principle, the luster is determined by the properties of the base. Adding the necessary pigment can only have an adverse effect on the gloss: if the pigment is not best dispersed, some pigment agglomeration particles will have an adverse effect on the surface evenness, thus reducing the gloss due to the diffuse of light.
2. Patience: weather resistance and chemical resistance will also be determined by the choice of paint base. Inadequate dispersion of pigment particles will also reduce patience. The pigment particles on the surface provide an attack point for chemicals and climatic factors. On the other hand, if the correct selection of the pigment is best dispersed, it can only improve the durability of the coating system, for example, by reflecting (TiO2) or absorbing UV radiation (iron oxide red) to improve the weatherability. Proper dispersion of pigment or pigment can also improve the chemical resistance of lacquer base.
3. Storage period: the storage life of the coating system depends largely on the quality of pigment dispersion. When there are too many coarse pigments in the system, the adverse effects of coarse particle precipitation are easy to understand. Such stability is caused by the so-called pigment &ldquo, after wetting &rdquo, or by the opposite pigment re flocculation. The wetting can be given if the pigment is not completely re flocculated when it begins to disperse to complete dispersion. The reason for the further flocculation of the previously properly dispersed pigment dispersion is that the pigment slurry is stable enough. This depends to a great extent on the stability of the dispersing paint base or the ratio of paint to solvent in the dispersion process. Solvents generally have excellent wetting properties, while lacquer base is good for stability. The problem is wetting (= solvent) and stability (= lacquer) to achieve the desired combination.
4, color, color intensity, transparency, and covering power: all of these properties depend largely on the surface of the pigment used by the &ldquo, the best dispersion of ” The full dispersion of the pigment in the case of covered pigments can lead to an increase in the covering power, which makes the color intensity of the coloured pulp greater (without flocculation); and in the case of transparent pigments, the transparency is better. For all pigments, the full dispersion of pigment can result in the hue and &ldquo of the color. The purity of the pigment is &rdquo.