Sericite

Sericite is a silicate mineral with a fine scale-like structure. It has fine particles and easy hydration. There is less cation replacement in the structure. The amount of K+ filled in the interlayer is less than that of muscovite, so the potassium content in the chemical composition is slightly lower than that of muscovite. But the water content is higher than that of muscovite, so some people call it a polysilicon, potassium-poor, water-rich clay mica.

Application of sericite in the field of coatings

Superfine sericite powder is a new type of functional filler, which is widely used in the field of paints and coatings. Because sericite powder has fine scale shape, smooth crystal surface, large diameter-to-thickness ratio, high whiteness, stable chemical properties, light weight, smoothness, insulation and radiation resistance, it is widely used in various high-grade paints, rust-proof, fire-proof and anti-corrosion coatings. good pigment filler. Due to the layered structure of sericite, the paint film can be maintained for a long time without fading after the dye particles enter the lattice layers of sericite.

The chemical nature of sericite is similar to that of traditional coating fillers such as talc, kaolin, wollastonite, etc., and both belong to silicate minerals, but its unique structure and special properties make it affect the relevant properties of coatings in applications, for example, in It has a plane enhancement effect in the paint. Using superfine sericite powder to replace traditional inorganic fillers in coating formulations can significantly enhance the strength of the coating film and the adhesion between the coating film and the substrate, improve the integrity, weather resistance, acid and alkali resistance of the coating, and improve the paint film smoothness. Applied to exterior wall coatings, it can improve its heat resistance, anti-fouling, anti-radiation and other properties.

Wet-milled sericite powder can be added to high-grade paints to replace zinc powder, aluminum powder, titanium powder, etc. Wet-milled sericite powder has been widely used in standard linseed oil civil paint, butadiene milk, propylene, polyvinyl acetate. Fat milk and acrylic milk and other interior wall paints, as well as automobile, motorcycle, ship paint, etc.

After adding superfine sericite powder to steel structure fireproof coating, its related properties are greatly improved. Adding sericite powder modified by titanate coupling agent, the heat resistance limit of fireproof coating is increased by 25 ℃, water resistance The limit is increased from 28h to 47h, and the bond strength is increased from 0.45MPa to 1.44MPa.

Adding an appropriate amount of superfine sericite powder to the rust conversion coating can enhance the heat resistance, weather resistance, water resistance, corrosion resistance and comprehensive mechanical properties of the coating film.

After adding ultra-fine sericite powder to anti-corrosion coatings, the surface hardness, flexibility, adhesion and impact resistance of the coating film are improved; At the same time, it can replace or partially replace titanium dioxide in the coating formulation to reduce costs without affecting the coating performance.