Patent US3520960A successfully refreshed from Google Patents.
US3520960A
Expired / Lapsed
US
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Method of making microphorous cellulose nitrate films
Assignee: Massachusetts Institute of Technology
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Filing: 1967-03-22
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Granted: 1970-07-21
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Expires: 1987-03-22
Abstract
No abstract record available.
Inventors
- 👤 Allan S Douglas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:08
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/08; B01D71/12; B01D71/20; B01D67/00; B01D67/0002; B01D67/0009; B01D67/0011; B01D67/0023; B01D67/003; C; C08; C08J; C08J9/00; C08J9/26; C08J2201/00; C08J2201/04; C08J2201/044; C08J2201/0444; C08J2201/05; C08J2201/0502; C08J2301/00; C08J2301/08; C08J2301/16; C08J2301/18
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-07-20 | 1974-01-19 | 1974-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-07-20 | 1978-01-19 | 1978-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-07-20 | 1982-01-19 | 1982-07-21 | $7700.00 | Window Closed / Lapsed |