Pigments and their preparation by coating with oxides of Si-Zr-Al
US4447271A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1982 |
| Grant date | May 8, 1984 |
| Priority date | — |
| Expiry date | Sep 30, 2002 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/90
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Titanium dioxide pigment having a high durability when used in paints comprises a particulate core of rutile titanium dioxide having an inner coating of dense amorphous silica on which is carried an outer coating of a hydrous oxide of zirconium. Optionally the pigment has an outer coating of a hydrous oxide of aluminum. The amount of dense amorphous silica is up to 12% by weight expressed as SiO.sub.2 and the amount of hydrous oxide of zirconium is up to 5% expressed as ZrO.sub.2 on the weight of TiO.sub.2. The outer coating of hydrous oxide of aluminium can be present in an amount of up to 6% by weight expressed as Al.sub.2 O.sub.3 on the weight of TiO.sub.2. A combination of these coatings has been found to be extremely advantageous in producing a paint containing the pigment having a very good durability and resistance to weathering.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.