Matting agents is polypropylene acid ester with epoxy resin. It is the matting resin of outdoor powder coatings. Its good performance makes it can get 1-60% any gloss and suitable for gloss of 1-30% outdoor polyester powder extinction.
The matting agent surface with organic treatment has a certain degree of improvement on the paint film scratch and wear resistance of the surface. The larger the average particle size, the higher the extinction efficiency. Amount of matting agent depending on the resin system, solid content, dry film thickness, matting agent types, dry method and the required gloss.
Natural silica processing quartz sand (powder) by grinding, but it has more impurities content, its main components is silica, so it cannot called white carbon black, nor matting properties. So it only used as filler in paint. While white carbon black matting agents for paints mainly are synthetic silica, which is divided into fumed and precipitated white carbon black. The micro-structure is amorphous or glassy.
Varnish coating without matting agent presents a mirror film leveling state. When light reaches the mirror membrane surface, part of the incident light is absorbed and part is reflected, and reflection part makes the films luster. Film containing silica matting agents, white carbon black particles distributed evenly over paint film form a slightly rough surface. It can be seen that matting agent particles evenly distributed in the film from the film section of the scanning electron microscope photo. When the incident light reaches the rugged surface of the paint film to has diffuse reflection, that is scattering occurs matte low gloss and matte appearance. High porosity, optimal particle size distribution as well as proper surface treatment of silica matting agents can get the best matting effect. The selection about matting agents and more details will be explained next time, follow OKCHEM Linkedin can help you get more news and knowledge about chemicals raw materials.