Titanium dioxide in paint industry is the most important white pigment, which provides an excellent white effect by scattering light. Not only white paint needs it, but other color paints also need it as a basic pigment to provide hiding power. Whether the paint is wet, dry or re-wet, titanium dioxide can provide whiteness and hiding power for flat or high-gloss paints. For coatings, titanium dioxide is an indispensable pigment.
Next, we will introduce the requirements of titanium dioxide paint coating.
1. Dispersibility / Hiding Power
The paint is applied to the surface of the building as a decorative paint, so its aesthetics is particularly important. There are two requirements for aesthetics. One is to cover the color of the building itself, and the other is to provide a layer of uniformly colored decorative coating. In other words, the hiding power of the coating must be high, and its hiding power mainly comes from titanium dioxide. Therefore, the hiding power of titanium dioxide is very important.
The hiding power is mainly affected by the dispersibility of titanium dioxide and the particle size. The finer the particles and the better the dispersibility, the higher the hiding power. Only by improving the dispersibility of titanium dioxide can the true hiding power of titanium dioxide be fully exerted, thereby improving the hiding power of the entire coating film.
2. Weather Resistance
The weatherability of exterior wall coating, namely outdoor durability, refers to the change degree of mechanical properties such as modulus, strength, cohesiveness, color and light retention of exterior wall coating exposed to outdoor environment conditions, and whether embrittlement, pulverization, discoloration, gloss loss, peeling and other phenomena occur. The main function of exterior wall paint is protection and decoration. The coating film must be able to be maintained until the next update and maintain a good visual effect. Therefore, weather resistance is very important.
3. Settlement Resistance
The most common unstable state of the paint in the container is the liquid-solid phase separation of the paint during storage, that is, delamination or syneresis. As a result, the paint cannot be evenly dispersed during use, which directly affects the hiding power and decorative effect of the paint. Therefore, the sedimentation resistance of titanium dioxide must be improved.
4. Color ability
When titanium dioxide in paint industry is applied in basic color matching coating, besides the covering power, the compatibility and color matching stability with other pigments or dyes are mainly considered, because it has a great influence on the color uniformity and chromaticity of the coated film. If the titanium dioxide is not compatible with other pigments or dyes in the color paste, the color coating will have the defect of uneven color. Even if it is uniformly dispersed under the action of high-speed shearing force, the pigment migration will occur during use or the drying process of the coating film, resulting in uneven color of the coating film.