Anti-corrosion coating definition: fumed silica Definition of anti-corrosion coating: Anti-corrosion coating refers to a type of liquid or solid material that can form a film on the surface of an object under certain conditions for protection, decoration or other special functions (insulation, rust, mildew, heat resistance, etc.). . Because most of the early coatings used vegetable oil as the main raw material, they were also called paints. Synthetic resins have replaced most or all of vegetable oils, so they are called coatings. There are three main functions: protection, decoration, and cover up the defects of the product, and enhance the value of the product.
 
In anti-corrosion coating formulations, silica is used as a thickening thixotropic and anti-settling additive. Thickening, plays the role of anti-settling, suspension, etc., so that the filler and other additives can be dispersed evenly in the resin without precipitation; Improve construction performance.


     Mechanism of action: When silica is dispersed in a non-polar liquid, the silanol groups on the surfaces of different particles form bridges through hydrogen bonding interactions, and the formation of this three-dimensional structure produces a thickening effect. When the system is subjected to mechanical external force, such as stirring or shaking, this structure is damaged. The type and duration of the mechanical external force applied determine the degree of damage. As a result, the thickened system becomes liquid again. If kept at rest, the silica particles will join together to restore the original viscosity. This phenomenon is called pseudoplasticity.
Most of the anti-corrosion coatings are epoxy resin, polyurethane resin, vinyl resin and other systems. These resins have strong polar groups. Generally, hydrophilic fumed silica is used, which is prone to solvent-based effects. The consistency and suspension effect is very good, but within a week to ten days, the polar groups destroy the hydrogen bonds that form the network structure, resulting in the cracking of the hydrogen bonds, thinning, no thixotropy, filler precipitation and other problems, so, It is recommended to use hydrophobically modified fumed silica for anti-corrosion coatings, which has strong stability and avoids solvent-based effects.