Patent US3753923A successfully refreshed from Google Patents.
US3753923A
Expired / Lapsed
US
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Manufacture of expanded vermiculite employing a urea compound and low temperatures
Assignee: Takeda Pharmaceutical Co Ltd
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Filing: 1971-10-04
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Granted: 1973-08-21
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Expires: 1991-10-04
Abstract
Abstract EXPANDED VERMICULITE IS PREPARED BY A PROCESS COMPRISIN IMPREGNATING VERMICULITE WITH AT LEAST A UREA COMPOUND SELECTED FROM THE GROUP CONSISTING OF UREA AND THIOUREA AND HEATING THE RESULTING COMPOSITION AT A TEMPERATURE NOT LOWER THAN THE DECOMPOSITION POINT OF THE UREA COMPOUND IN THE COMPOSITION. THE EXPANDED VERMICULITE HAS DESIRABLE PROPERTIES AND IS USED IN WIDELY VARIED INDUSTRIAL APPLICATION.
Inventors
- 👤 T Wada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:35
CPC Classifications
C; C04; C04B; C04B14/00; C04B14/02; C04B14/04; C04B14/20; C04B14/204; Y; Y10; Y10S; Y10S106/00; Y10S106/03
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) | 1976-08-20 | 1977-02-19 | 1977-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-20 | 1981-02-19 | 1981-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-20 | 1985-02-19 | 1985-08-21 | $7700.00 | Window Closed / Lapsed |