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US3112997A
Expired / Lapsed
US
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Process for producing pure crystalline silicon by pyrolysis
Assignee: Merck and Co Inc
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Filing: 1961-11-01
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Granted: 1963-12-03
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Expires: 1981-11-01
Abstract
No abstract record available.
Inventors
- 👤 Walter C Benzing
- 👤 Schaarschmidt Edwa Christopher
- 👤 Robert E Grammer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:41
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/02; C01B33/021; C01B33/027; C01B33/029
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2935386A
Cited
US3014791A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1966-12-02 | 1967-06-03 | 1967-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-12-02 | 1971-06-03 | 1971-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-12-02 | 1975-06-03 | 1975-12-03 | $7700.00 | Window Closed / Lapsed |