Patent US3787370A successfully refreshed from Google Patents.
US3787370A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of substan-tially linear polyesters of low free carboxyl group content
Assignee: Teijin Ltd
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Filing: 1972-03-14
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Granted: 1974-01-22
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Expires: 1992-03-14
Abstract
Abstract A PROCESS FOR THE PREPARATION OF SUBSTANTIALLY LINEAR, FIBER-FORMING OR FILM-FORMING POLYESTERS FROM A DICARRBOXYLIC ACID OR ITS ESTER-FORMING DERIVATIVE, OR A HYDROXYCARBOXYLIC ACID OR ITS ESTER-FORMING DERIVATIVE, AND A GLYCOL OR ITS ESTER-FORMING DERIVATIVE, SUCH PROCESS BEING CHARACTERIZED BY ADDITION OF AT LEAST ONE SPECIFIC ORTHOCARBONATE OR A CERTAIN STAGE OF THE POLYCONDENSATION REACTION TO THEREBY FORM POLYESTERS HAVING A LOW FREE CARBOXYL GROUP CONTENT.
Inventors
- 👤 T Shima
- 👤 T Urasaki
- 👤 I Oka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:24
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/06; C08G63/065; C08G63/12; C08G63/16; C08G63/20; C08G63/46; C08G63/78
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |