US2516548A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of anatase titanium dioxide pigments
Assignee: Wyeth Holdings LLC
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Filing: 1945-09-25
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Granted: 1950-07-25
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Expires: 1965-09-25
Abstract
No abstract record available.
Inventors
- 👤 Winfred J Cauwenberg
- 👤 Jr Charles A Tanner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:46
CPC Classifications
C; C01; C01G; C01G23/00; C01G23/04; C01G23/047; C01G23/0475
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
101 words
A METHOD OF PRODUCING ANATASE TITANIUM DIOXIDE PIGMENTS OF IMPROVED TINTING STRENGTH WHICH COMPRISES ROASTING A TITANIUM SULFATE HYDROLYSATE CONTAINING A SMALL AMOUNT OF AN ALKALI METAL COMPOUND AT A TEMPERATURE AND FOR A TIME SUFFICIENT TO CONVERT THE HYDROLYSATE TO SMALL ANATASE CRYSTALS BUT INSUFFICIENT TO DEVELOP PIGMENT PROPERTIES THEREIN AND THEN REMOVING THE ALKALI METAL FROM THE ANATASE TITANIUM DIOXIDE AND CALCINING IT AT TEMPERATURES OF ABOUT 900*C. TO 1050*C. IN THE PRESENCE OF A QUANTITY OF PHOSPHATE CORRESPONDING TO AT LEAST 0.4% AND NOT MORE THAN ABOUT 0.8% OF P2O5, BASED ON THE WEIGHT OF THE TITANIUM DIOXIDE.
References Cited (Backward Citations)
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GB360436A
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GB392194A
Cited
US2055221A
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US2131841A
Cited
US2273431A
Cited
US2307048A
Cited
US2358167A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-07-24 | 1954-01-23 | 1954-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-07-24 | 1958-01-23 | 1958-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-07-24 | 1962-01-23 | 1962-07-25 | $7700.00 | Window Closed / Lapsed |