US3679604A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ultra-stable 3-angstrom molecular sieve
Assignee: WR Grace and Co
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Filing: 1970-09-21
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Granted: 1972-07-25
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Expires: 1990-09-21
Abstract
Abstract ULTRA-STABLE 3 A. ZEOLITE A MOLECULAR SIEVES CAN BE PRODUCED FROM 4 A. ZEOLITE A MOLECULAR SIEVES BY THE CONCURRENT OF SEQUENTIAL EXCHANGE OF THE 4 A. ZEOLITE USING POTASSIUM AND RARE EARTH IONS. THE RESULTING 3 A. ZEOLITE A HAS A HIGH STEAM AND THERMAL STABILITY, IS VERY USEFUL AS AN ADSORBENT, AND CAN BE REACTIVED USING EXTREME ENVIRONMENTS FOR A SUBSEQUENT REUSE.
Inventors
- 👤 Hanju Lee
- 👤 Dongsuk Chi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:25
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/02; B01J20/10; B01J20/16; B01J20/18; B01J20/186; Y; Y10; Y10S; Y10S423/00; Y10S423/24
Claims Analysis
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |