US3766145A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of unsaturated polyesters of isophthalic acid
Assignee: Sun Research and Development Co
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Filing: 1971-08-06
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Granted: 1973-10-16
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Expires: 1991-08-06
Abstract
Abstract POLYANHYDRIDE OF ISOPHTHALIC ACID AND EITHER FUMARIC ACID OR MALEIC ACID IS PREPARED CHEMICALLY OR THERMALLY. THIS POLYANHYDRIDE IS REACTED WITH AN ETHYLENE EPOXIDE OR PROPYLENE EPOXIDE TO PRODUCE A POLYESTER HAVING ETHYLENICALLY UNSATURATED DOUBLE BONDS USEFUL AS CROSS-LINKING SITES.
Inventors
- 👤 R Thompson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:43
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/12; C08G63/52; C08G63/56; C08G63/58; C08G63/54; C08G67/00; C08G67/04
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) | 1976-10-15 | 1977-04-16 | 1977-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-15 | 1981-04-16 | 1981-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-15 | 1985-04-16 | 1985-10-16 | $7700.00 | Window Closed / Lapsed |