US3748272A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Desiccants with moisture indicator
Assignee: Merck Patent GmbH
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Filing: 1970-09-11
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Granted: 1973-07-24
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Expires: 1990-09-11
Abstract
Abstract DESICCANT COMPOSITIONS CONTAINING AS A DESICCANT CONCENTRATED SULFURIC ACID OR PHOSPHORUS PENTOXIDE, IN ADMIXTURE WITH A SOLID CARRIER AND A DYESTUFF WHICH EXHIBITS A DIFFERENT COLOR IN THE PRESENCE OF HYDRATED DESICCANT, E.G., 1-HYDROXY-4-(2-SULFO - 4,6 - DINITROPHENYLAZO)-NAPHTHALENE WHEN SULFURIC ACID IS EMPLOYED AS DESICCANT AND NEUTRAL RED WHEN PHOSPHORUS PENTOXIDE IS EMPLOYED.
Inventors
- 👤 A Wenz
- 👤 A Litters
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:39
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/26; Y; Y10; Y10S; Y10S252/00; Y10S252/963
Claims Analysis
Total Claims: 0
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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) | 1976-07-23 | 1977-01-22 | 1977-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-23 | 1981-01-22 | 1981-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-23 | 1985-01-22 | 1985-07-24 | $7700.00 | Window Closed / Lapsed |