Application of Mica Powder in Coatings
Nov. 20, 2020
1.Barrier effect. The flaky filler forms a basically parallel orientation arrangement in the paint film, and the penetration of water and other corrosive substances into the paint film is strongly blocked. When high-quality sericite powder is used, water and other corrosive substances penetrate The penetration time of the paint film is generally extended by 3 times. Because the Mica powder filler is much cheaper than the resin, it has very high technical and economic value. The use of high-quality sericite powder is an important means to improve the quality and performance of anti-corrosion coatings and exterior wall coatings. During the coating process, the sericite wafers lie down under the action of surface tension before the paint film is cured, and automatically form a structure parallel to each other and the surface of the paint film. Such layer-by-layer arrangement, its orientation is exactly perpendicular to the direction in which corrosive substances penetrate the paint film, and the barrier effect is most fully exerted.
2. Improve the physical and mechanical properties of the paint film. Using sericite powder can improve a series of physical and mechanical properties of the paint film. The key is the morphological characteristics of the filler, that is, the diameter-to-thickness ratio of the flaky filler and the length-to-diameter ratio of the fibrous filler. The particle-filled filler is like the sand in the concrete, which acts as a reinforcing steel.
3. Improve the anti-wear performance of the paint film. The hardness of the resin itself is limited, and the strength of many fillers is not high. On the contrary, sericite is one of the components of granite, and its hardness and mechanical strength are great. Therefore, adding sericite powder as a filler in the coating can significantly improve its anti-wear performance. Sericite powder is mostly used in automotive coatings, road coatings, mechanical anti-corrosion coatings, and wall coatings.
4. Insulation performance. Sericite has extremely high resistance and is itself the most excellent insulating material. It forms a compound with silicone resin or silicone boron resin, which is converted into ceramic substances with good mechanical strength and insulation performance when encountering high temperatures. Therefore, wires and cables made of this type of insulating material can even be burned in a fire. , Still maintain the original insulation state. This is very important for mines, tunnels, special buildings, special facilities, etc.
5. Flame-retardant. sericite powder is a valuable flame-retardant filler. If it is combined with organic halogen flame retardants, flame-retardant and fire-resistant coatings can be prepared.
6. Anti-ultraviolet and infrared performance. Sericite has excellent shielding properties of ultraviolet and infrared rays. Therefore, adding wet sericite powder to outdoor paint can greatly improve the UV resistance of the paint film and delay the aging of the paint film. Its infrared shielding performance is used to prepare heat preservation and heat insulation materials.
7. Heat radiation and high-temperature. Phlogopite has good infrared radiation ability. If it is combined with iron oxide, it can produce excellent heat radiation effect.
8. Sound insulation and shock absorption effect. Sericite can significantly change a series of physical moduli of the material, forming or changing the viscoelasticity of the material. This kind of material efficiently absorbs vibration energy and weakens vibration and sound waves. In addition, shock waves and sound waves form repeated reflections between mica wafers, which also weaken their energy. Sericite powder is also used to formulate noise reduction, sound insulation and shock absorption coatings.
Muscovite and Phlogopite have good electrical insulation, non-conductivity, acid resistance, alkali resistance and voltage resistance, so they are widely used to make insulating materials in the electronics and electrical industries.