Patent US2989499A successfully refreshed from Google Patents.
US2989499A
Expired / Lapsed
US
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Process employing catalyst
Assignee: Celanese Corp
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Filing: 1958-04-15
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Granted: 1961-06-20
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Expires: 1978-04-15
Abstract
No abstract record available.
Inventors
- 👤 Robert G Linville
- 👤 Robert J Osborne
- 👤 Charles L Smart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:40
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78; C08G63/82; C08G63/87; C08G63/83
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
58 words
IN THE PROCESS FOR THE PRODUCTION OF LINEAR FILAMENTFORMING POLYESTERS BY THE CONDENSATION OF AN ESTER OF A DICARBOXYLIC ACID AND A GLYCOL IN THE PRESENCE OF A CATALYST COMPRISING A ZINC SALT OF A FATTY ACID, THE IMPROVEMENT WHICH COMPRISES ADDING A MEMBER OF THE GROUP CONSISTING OF MAGNESIUM AND CALCIUM HYPOPHOSPHITES TO THE RESULTING FILAMENT-FORMING POLYESTER.
Claim 2
Dependent Claim
58 words
IN THE PROCESS FOR THE PRODUCTION OF LINEAR FILAMENTFORMING POLYESTERS BY THE CONDENSATION OF AN ESTER OF A DICARBOXYLIC ACID AND A GLYCOL IN THE PRESENCE OF A CATALYST COMPRISING A ZINC SALT OF A FATTY ACID, THE IMPROVEMENT WHICH COMPRISES ADDING A MEMBER OF THE GROUP CONSISTING OF MAGNESIUM AND CALCIUM HYPOPHOSPHITES TO THE RESULTING FILAMENT-FORMING POLYESTER.
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) | 1964-06-19 | 1964-12-19 | 1965-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-06-19 | 1968-12-19 | 1969-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-06-19 | 1972-12-19 | 1973-06-20 | $7700.00 | Window Closed / Lapsed |