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Silicon Dioxide Used in Coating and Painting
Jun 21, 2018

                                     Precipitated Silica (SiO2) Used in Painting and Coating



The precipitated silica is commonly called white carbon black, also called hydrated silicic acid and light silica. The chemical expression is generally written as SiO2. The appearance is amorphous powder with high dispersion in white, and it is also processed into granular as a commodity. The proportion is 2.319 to 2.653, and the melting point is 1750. Insoluble in water and most acids, it will become fine aggregates after absorbing moisture in air. It can be dissolved in caustic sodium and hydrofluoric acid. For other chemicals stable, high temperature, no decomposition, no burning. It has high electrical insulation, porous nature, large internal surface area, water absorption and innocuity. CAS NO:7631-86-9.

White carbon black has thixotropic properties, and a small amount of silica is added to the coating to eliminate the droplet deposition. In unsaturated polyester coatings, as long as 0.5 ~ 2% concentration of white carbon black is added, the coating can be coated on the vertical surface every time 500g/m2 does not produce droplets and wrinkles. Adding silica to pigments can not only prevent pigments from precipitating, but also improve the adsorption of pigments and dyes and improve their dispersivity. When used as an emulsion coating filler, the thermal stability can be improved. In order to meet the requirements of white paint and ink matting agent, we have developed and produced special matting agents abroad. When nitro varnish and similar coatings contain precipitated white carbon black light elimination agent, it can improve the non precipitation performance of the paint, and can make the paint easy to disperse, only a small amount of thickening effect, good suspension, excellent light extinction, high transparency and good wear resistance. The printing ink added 0.5% white carbon black, the printing effect is good, can eliminate the influence of the undispersed ink penetration, improve the washability of the printing material, and increase the gloss of the color.