Titanium dioxide pigment coated with silica and alumina
Abstract
Abstract IMPROVED TITANIUM DIOXIDE PIGMENTS HAVING HIGH OPACITY AND OUTSTANDING EASE OF DISPERSIBILITY IN LIQUID COATING COMPOSITIONS ARE PREPARED BY WET TREATMENT OF A TITANIUM DIOXIDE BASE PIGMENT BY PROCESSES WHEREIN FROM 0.5 TO 25 PERCENT OF DENSE SILICA IS PRECIPITATED AS A DENSE, ADHERENT COATING ON THE TITANIUM DIOXIDE, AND THEREAFTER FROM 0.1 TO 10 PERCENT OF ALUMINA IS PRECIPITATED IN AN AQUEOUS SLURRY OF THE SILICA-COATED PIGMENT, THE PERCENTS OF SILICA AND ALUMINA BOTH BEING BY WEIGHT, BASED ON THE WEIGHT OF TITANIUM DIOXIDE. THE TREATED PIGMENT IS RECOVERED, DRIED AND PREFERABLY DRY-MILLED. PAINTS MADE WITH THE FINISHED PIGMENTS HAVE EXCELLENT SMOOTHNESS AND OUTSTANDING DURABILITY UPON OUTDOOR EXPOSURE.
Inventors
No inventors recorded.
Bibliographic Details
Claims Analysis
Total Claims: 0References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-26 | 1977-05-28 | 1977-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-26 | 1981-05-28 | 1981-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-26 | 1985-05-28 | 1985-11-27 | $7700.00 | Window Closed / Lapsed |