Fillers in coatings have a great influence on the properties of most colored coatings. There are many kinds of fillers. Because of its high whiteness, soft quality, easy dispersion and suspension in water, good acid solubility, low cation exchange capacity and good fire resistance, high purity kaolin has become an essential mineral raw material in the coating industry.
The main function of kaolin in paint is filling and pigment substitute. Adding a certain amount of filler in the coating can improve the filling, grinding and mechanical strength of the coating. Kaolin is mainly used to replace white pigment in paint industry, especially titanium dioxide; Different particle size and types of kaolin are used in different types of paint: coarse kaolin is used in dull gloss or flat gloss paint, fine kaolin is used to produce high gloss paint, or to manufacture emulsion pigment, which can make the coating have better opacity, anti-corrosion and anti sedimentation, improve the hardness and quality of the coating.
After calcined kaolin is added into the coating, it can shield the ultraviolet radiation, improve the weatherability of the coating, delay the pulverization and discoloration, enhance the comprehensive mechanical properties and pollution resistance of the coating, self-cleaning, acid, alkali and high temperature resistance, and improve the heat resistance and corrosion resistance of the coating.
The market of calcined kaolin products still has great growth potential. The calcined kaolin used in coatings needs to have the characteristics of high whiteness, low viscosity and fine particle size.