US2668162A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of high molecular weight polyhydroxyacetic ester
Assignee: EIDP Inc
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Filing: 1952-03-20
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Granted: 1954-02-02
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Expires: 1972-03-20
Abstract
No abstract record available.
Inventors
- 👤 Charles E Lowe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 15:52
CPC Classifications
C; C07; C07D; C07D319/00; C07D319/10; C07D319/12; C08; C08G; C08G63/00; C08G63/02; C08G63/06; C08G63/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
52 words
A PROCESS FOR PREPARING POLYHYDROXYACETIC ESTERS WHICH COMPRISES POLYMERIZING GLYCOLIDE BY HEATING GLYCOLIDE, FREE OF WATER AND ACID IMPURITIES, AT A TEMPERATURE OF FROM ABOUT 150* C. TO ABOUT 245* C. IN THE PRESENCE OF A CATALYTIC AMOUNT OF AN ANTIMONY COMPOUND FROM THE GROUP CONSISTING OF ANTIMONY TRIOXIDE AND ANTIMONY TRIHALIDES.
Claim 2
Dependent Claim
52 words
A PROCESS FOR PREPARING POLYHYDROXYACETIC ESTERS WHICH COMPRISES POLYMERIZING GLYCOLIDE BY HEATING GLYCOLIDE, FREE OF WATER AND ACID IMPURITIES, AT A TEMPERATURE OF FROM ABOUT 150* C. TO ABOUT 245* C. IN THE PRESENCE OF A CATALYTIC AMOUNT OF AN ANTIMONY COMPOUND FROM THE GROUP CONSISTING OF ANTIMONY TRIOXIDE AND ANTIMONY TRIHALIDES.
References Cited (Backward Citations)
US2585427A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-02-01 | 1957-08-03 | 1958-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-02-01 | 1961-08-03 | 1962-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-02-01 | 1965-08-03 | 1966-02-02 | $7700.00 | Window Closed / Lapsed |