| 摘要 |
<p>A coated titanium dioxide pigment, and the process for its preparation, consisting essentially of a core of pigmentary titanium dioxide (TiO2), a porous inner coating of at least one hydrous oxide selected from the group consisting of silica (SiO2) and alumina (Al2O3), said silica being present in an amount less than 12% by weight, based on the uncoated pigment, and said alumina being present in an amount less than 11% by weight, based on the uncoated pigment, and a dense outer coating of silica in an amount between about 2% and about 17% by weight, based on the uncoated pigment. Optionally the coated pigment can have an additional coating of porous Al2O3, up to 5%. As a component of coating compositions, this pigment provides a high degree of hiding power and durability.</p> |
