Сульфатный или хлоридный процесс получения диоксида титана: какой лучше для покрытий?
Лакокрасочная промышленность является крупнейшим потребителем диоксида титана (TiO₂), особенно диоксида титана рутилового типа, причем большая его часть потребляется сектором лакокрасочной промышленности. Во всем мире потребление TiO₂ лакокрасочной промышленностью составляет около 58%–60% от общего использования пигмента диоксида титана. В Китае эта доля еще выше, около 60%–65%. Диоксид титана является наиболее широко используемым пигментом в лакокрасочной промышленности, на его долю приходится половина затрат на пигменты и приблизительно 90% от общего потребления пигментов в отрасли. Он также составляет около 10%–25% затрат на сырье в покрытиях.
Depending on the specific performance requirements of different types of coatings, properties such as weather resistance, hiding power, appearance, and dispersibility of titanium dioxide are critical. The performance of titanium dioxide produced by the two different processes—the sulphate process and the chloride process—can be compared as follows:
- In terms of usage, sulphate-process rutile titanium dioxide typically requires 5% to 15% more quantity compared to chloride-process rutile titanium dioxide.
- In terms of dispersibility, sulphate-process rutile titanium dioxide is approximately 10% inferior to chloride-process rutile titanium dioxide.
- In terms of hiding power, chloride-process rutile titanium dioxide has 10% to 15% higher hiding efficiency compared to sulphate-process rutile titanium dioxide.
- In surface properties, flowability, yellowing resistance, and color stability, chloride-process rutile titanium dioxide also outperforms sulphate-process products.
Therefore, it is very important for customers to select the titanium dioxide variety that meets the performance requirements of their coatings and finished films. From the comparison, it is clear that currently, the best titanium dioxide is the rutile type produced by the chloride process. It is the highest-quality white pigment available on the market, offering excellent overall performance, making it the first choice for coatings, and an essential pigment for light-colored paints.
Due to differences in surface treatment processes, there are various grades of titanium dioxide available. Specific grades can be selected according to the characteristics of the coating being formulated, such as whether high gloss, high hiding power, or high chalking resistance is required.
Titanium dioxide produced by the sulphate process has a lower anatase-to-rutile phase transformation rate compared to the chloride process, resulting in slightly lower whiteness and light stability. However, it comes at a lower price point.or expert advice.
