US3690907A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing clay-base pigment
Assignee: Dow Chemical Co
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Filing: 1970-05-20
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Granted: 1972-09-12
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Expires: 1990-05-20
Abstract
Abstract A METHOD OF PRODUCING A CLAY-BASE PIGMENT WITH IMPROVED OPTICAL PROPERTIES WHICH COMPRISES FORMING AN AQUEOUS MIXTURE OF CLAY WITH AN ALKALINE EARTH METAL HYDROXIDE, E.G. CALCIUM HYDROXIDE, AND AGING THE MIXTURE AT ELEVATED TEMPERATURES.
Inventors
- 👤 Roger D Kroening
- 👤 David B Kirby
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 00:56
CPC Classifications
D; D21; D21H; D21H19/00; D21H19/36; D21H19/38; D21H19/385; C; C09; C09C; C09C1/00; C09C1/40; C09C1/42; C01; C01P; C01P2006/00; C01P2006/60
Claims Analysis
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References 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) | 1975-09-12 | 1976-03-13 | 1976-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-12 | 1980-03-13 | 1980-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-12 | 1984-03-13 | 1984-09-12 | $7700.00 | Window Closed / Lapsed |