The Main Method for Improving the
Weather Resistance of Titanium Dioxide
Weather resistance is one of the pigment properties of titanium dioxide. After the pigment is painted and coated, the coating will be exposed to sunlight, rain, sunlight, oxygen, water and temperature. and weight loss and other aging phenomena, pigments have the ability to resist the above changes (or the ability to resist ultraviolet erosion), which is called weather resistance. So what are the main ways to improve the weather resistance of titanium dioxide?
一. Reduce the size of titanium dioxide particles. The size of the particles is determined by the degree of aggregation of the titanium dioxide particles. The primary diameter of titanium dioxide particles is generally less than 1 micron. In latex paint, due to the adsorption of titanium dioxide itself, each particle will be close to each other. This leads to agglomeration of particles, which greatly increases the particle size of titanium dioxide. After treatment with polysilanol, the polarity of titanium dioxide particles can be eliminated, and the titanium dioxide particles will exist in the form of low-level aggregates, thus achieving the purpose of reducing the particle size of titanium dioxide.
二. The coating treatment of titanium dioxide. The photochemical activity of titanium dioxide is relatively strong, due to the existence of some defects in its crystal lattice. Under the action of sunlight, especially ultraviolet rays, water and catalysts, the Ti4+ in titanium dioxide is easily reduced to Ti3+, and at the same time, it releases carbon dioxide. The highly reactive nascent oxygen causes the organic matter as the binder to be oxidized, the polymer chain is broken and degraded, and soluble or volatile substances are formed, thereby destroying the continuity of the coating. A "dense film" is coated on the surface of the titanium dioxide particles to prevent direct ultraviolet radiation, and to isolate the titanium dioxide particles from the organic matter of the paint base, reduce the destructive force of photochemical action, avoid degradation, and thus improve its weatherability.
