Preparation of Acid-Resistant Ultramarine Pigment by Dense Silica Coating Process
Acid-resistant ultramarine blue pigment with a silica shell was prepared by dense silica coating process. From X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) analysis, it was confirmed that silica in the coating is attached on the ultramarine particles surface by characterizing the composition of elements and the microstructure on the surface of the silica coated particles. Orthogonal experimental design was applied to optimize the operating conditions of the coating process. The best acid resistance for the coated ultramarine blue reached the ninth grade under the following conditions: silica adding rate of 5 g/h, solid content of 6 g/l in the slurry and coating time of 2.5 h.
Zhong Cao, Lixian Sun, Xueqiang Cao, Yinghe He
S. F. Li and M. Liu, "Preparation of Acid-Resistant Ultramarine Pigment by Dense Silica Coating Process", Advanced Materials Research, Vols. 233-235, pp. 246-249, 2011