US2676945A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Condensation polymers of hydroxyacetic acid
Assignee: EIDP Inc
•
Filing: 1950-10-18
•
Granted: 1954-04-27
•
Expires: 1970-10-18
Abstract
No abstract record available.
Inventors
- 👤 Norton A Higgins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:01
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/06
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
103 words
A PROCESS FOR POLYMERIZING HYDROXYACETIC ACID WHICH COMPRISES HEATING AND DISTILLING WATER RAPIDLY FROM HYDROXYACETIC ACID AT SUBSTANTIALLY ATMOSPHERIC PRESSURE AND AT TEMPERATURES UP TO ABOUT 205* C. UNTIL RAPID EVOLUTION OF WATER CEASES, HEATING AND DISTILLING GLYCOLIDE FROM THE RESULTING MATERIAL UNDER VACUUM AND AT TEMPERATURES ABOVE THE MELTING POINT OF THE MATERIAL BUT BELOW 245* C. UNTIL APPRECIABLE EVOLUTION OF GLYCOLIDE CEASES, COOLING THE MATERIAL, POWDERING THE MATERIAL, AND HEATING THE POWDER AT TEMPERATURES ABOVE 215* C. BUT BELOW THE MELTING POINT UNTIL A POLYHYDROXYACETIC ESTER HAVING A MELT VISCOSITY AT 245* C. OF NOT LESS THAN 400 POISES IS FORMED.
References Cited (Backward Citations)
US1095205A
Cited
US1995970A
Cited
US1976359A
Cited
US2362511A
Cited
GB550837A
Cited
GB583268A
Cited
US2437046A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-04-26 | 1957-10-26 | 1958-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-04-26 | 1961-10-26 | 1962-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-04-26 | 1965-10-26 | 1966-04-27 | $7700.00 | Window Closed / Lapsed |