US2720503A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Organo-magnesium halide catalysts for the preparation of polyesters
Assignee: Eastman Kodak Co
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Filing: 1952-10-03
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Granted: 1955-10-11
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Expires: 1972-10-03
Abstract
No abstract record available.
Inventors
- 👤 John W Wellman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:02
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78; C08G63/82; C08G63/83
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
21 words
A PROCESS FOR PREPARATION OF POLYESTER COMPRISING (A) CONDENSING UNDER SUBSTANTIALLY ANHYDROUS CONDITIONS AN AROMATIC DICARBOXYLIC ACID DIESTER HAVING THE FORMULA:
Claim 2
Dependent Claim
21 words
A PROCESS FOR PREPARATION OF POLYESTER COMPRISING (A) CONDENSING UNDER SUBSTANTIALLY ANHYDROUS CONDITIONS AN AROMATIC DICARBOXYLIC ACID DIESTER HAVING THE FORMULA:
References Cited (Backward Citations)
US2465319A
Cited
US2614120A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1958-10-10 | 1959-04-11 | 1959-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-10-10 | 1963-04-11 | 1963-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-10-10 | 1967-04-11 | 1967-10-11 | $7700.00 | Window Closed / Lapsed |