US3793249A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyesters of 2,2'-spirobi(chroman)diols
Assignee: Eastman Kodak Co
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Filing: 1971-06-30
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Granted: 1974-02-19
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Expires: 1991-06-30
Abstract
Abstract NOVEL HIGH MOLECULAR WEIGHT POLYMERS OF 2,2''-SPIROBI(CHROMAN)DIOLS, DICARBOXYLIC ACIDS OF FOUR OR MORE CARBON ATOMS AND OTHER DIOLS WHICH ARE USEFUL IN THE PREPARATION OF PHOTOGRAPHIC FILM BASES.
Inventors
- 👤 F Hamb
- 👤 J Wilson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:58
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/12; C08G63/16; C08G63/18; C08G63/19; G; G03; G03C; G03C1/00; G03C1/76; G03C1/795; G03C1/7954
Claims Analysis
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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) | 1977-02-18 | 1977-08-20 | 1978-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-18 | 1981-08-20 | 1982-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-18 | 1985-08-20 | 1986-02-19 | $7700.00 | Window Closed / Lapsed |