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Patent US3519635A successfully refreshed from Google Patents.
US3519635A
Expired / Lapsed
US
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Photochromic compositions of a thermoplastic polymer and a polymeric material
Assignee: Wyeth Holdings LLC
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Filing: 1968-04-18
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Granted: 1970-07-07
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Expires: 1988-04-18
Abstract
No abstract record available.
Inventors
- 👤 Lewis Smith Meriwether
- 👤 Edith Clara Breitner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:01
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/72; G03C1/73; C; C08; C08K; C08K5/00; C08K5/36; C08K5/45; C08K5/46; C09; C09B; C09B45/00; G03C1/725
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3361726A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-07-06 | 1974-01-05 | 1974-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-07-06 | 1978-01-05 | 1978-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-07-06 | 1982-01-05 | 1982-07-07 | $7700.00 | Window Closed / Lapsed |