Latex coating is a kind of popular architectural paint, which glows with beautiful color, smooth and exquisite texture, as well as implicit and elegant luster. In the formulation design of latex paint, the amount of titanium dioxide in the raw material cost accounts for a large proportion.
Different types of latex paints need to choose different characteristics of titanium dioxide as the pigment to make it have excellent product performance. Considering the effect of titanium dioxide on the properties of latex paint, the following factors should be considered in the selection.
As a kind of decorative coating on the surface of buildings, the beauty of whiteness latex paint is particularly important. The beauty has two requirements: one is to provide uniform color decorative coating; the second is to cover the color of the building itself. The whiteness of titanium dioxide is the result of the effect of titanium dioxide on light, which determines its ability to appear white in the paint.
Hiding power (HP) refers to the ability of pigments in the paint to cover the background color of an object when it is coated with a certain paint so that the background color is no longer revealed through the paint. The hiding power of pigment depends on its crystal structure, refractive index, light absorption ability, and light scattering ability. Pigments with high refractive index have higher hiding power.
Titanium dioxide is generally divided into rutile titanium dioxide and anatase titanium dioxide. Among the white pigments, rutile titanium dioxide has the highest hiding power. The larger the hiding power is, the less coating required and the lower the production cost will be.
Tinting strength refers to the ability of a mixture of titanium dioxide and another pigment to reveal its own color. In general, the basic paint of white toning is prepared with titanium dioxide, and then the color paste is added to the basic paint before coating to conduct on-site toning. When titanium dioxide is used in toning base coating, not only the hiding power but also the coloring power is considered. The greater the tinting strength, the smaller the dosage, which can reduce production costs.
When grinding and dispersing in the paint production plant, dispersing quality directly affects the length of grinding and dispersing time, which is one of the important economic indexes in paint production. In addition, grinding time is too long will increase equipment pollution, which will make the whiteness of the product worse. The dispersion of the advantages and disadvantages will not only affect the color of titanium dioxide, hiding power, oil absorption, and other indicators but also directly affect the product processing process and the final product gloss and weatherability.
Lightfastness and weatherability
The lightfastness and weatherability of titanium dioxide is an important index to measure the application performance of titanium dioxide, which refers to the mechanical properties of the coating, such as modulus, strength, adhesion, color retention, color retention and light retention degree of change, as well as whether catalysis, powder, discoloration, loss of light, peeling and so on. After applying titanium dioxide to relevant application fields (such as automobile paint, profile, etc.), this index appears more significant.
Titanium dioxide plays an important role in the coating industry. It can not only improve the physical and chemical properties of the coating, enhance chemical stability, but also save materials and increase variety. It is because of this superior performance of titanium dioxide that it has become the most essential white pigment in the production of coatings.