Patent US3723390A successfully refreshed from Google Patents.
US3723390A
Expired / Lapsed
US
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High pressure continuous process for polyesters from dicarboxylic acid anhydrides and monoepoxides
Assignee: Ashland LLC
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Filing: 1970-10-22
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Granted: 1973-03-27
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Expires: 1990-10-22
Abstract
Abstract A PROCESS IS DISCLOSED FOR THE PRODUCTION OF THERMOPLASTIC POLYESTER RESINS VIA A CONTINUOUS OPERATION WHEREIN A DICARBOXYLIC ACID ANHYDRIDE AND A TERMINAL MONOEPOXIDE ARE CONDENSED UNDER A PRESSURE-TEMPERATURE-TIME RELATIONSHIP ADAPTED TO EFFICIENTLY PROVIDE PRODUCTS CORRESPONDING STRUCTURALLY TO CONVENTIONALLY PREPARED POLYESTERIFICATION PRODUCTS AS WELL AS PROVIDING UNIQUE STRUCTURALLY COMPOSED VARIANTS THEREOF.
Inventors
- 👤 R Carpenter
- 👤 C Peterson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:42
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/12; C08G63/52; C08G63/56; C08G63/58; C08G63/40; C08G63/42
Claims Analysis
Total Claims: 0
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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) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |