Patent US2951828A successfully refreshed from Google Patents.
US2951828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of bead polymerizates from cyclic internal esters of alpha-hydroxy carboxylic acids
Assignee: C.H. Boehringer Sohn AG and Co KG
•
Filing: 1958-02-27
•
Granted: 1960-09-06
•
Expires: 1978-02-27
Abstract
No abstract record available.
Inventors
- 👤 Zeile Karl
- 👤 Konz Wilhelm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:02
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/06; C08G63/08; Y; Y10; Y10S; Y10S528/00; Y10S528/902
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
125 words
THE METHOD OF BEAD-POLYMERIZING LACTIDE, WHICH COMPRISES SUSPENDING SAID LACTIDE IN AN INERT ORGANIC HYDROCARBON IN WHICH THE LACTIDE IS SUBSTANTIALLY INSOLUBLE AND IN WHICH THE RESULTING POLYMER IS COMPLETELY INSOLUBLE AND HEATING SAID SUSPENSION TO A TEMPERATURE WITHIN THE RANGE OF 60 TO 180*C. FOR 3 TO 15 HOURS IN THE PRESENCE OF 0.05 TO 1.0% BY WEIGHT OF A DI-HYDROCARBON SILOXANE SILICONE OIL HAVING A VISCOSITY OF 50 TO 1500 CENTISTOKES, BASED ON THE WEIGHT OF LACTIDE, AND 0.1 TO 1.0 PART BY WEIGHT PER 100 PARTS OF STARTING MATERIAL OF A HALIDE OF A METAL SELECTED FROM THE GROUP CONSISTING OF METALS FROM GROUPS I, II, IV, V, VI AND VII OF THE PERIODIC SYSTEM OF ELEMENTS, WHILE CONTINUOUSLY STIRRING THE SUSPENSION.
Claim 2
Independent Claim
125 words
THE METHOD OF BEAD-POLYMERIZING LACTIDE, WHICH COMPRISES SUSPENDING SAID LACTIDE IN AN INERT ORGANIC HYDROCARBON IN WHICH THE LACTIDE IS SUBSTANTIALLY INSOLUBLE AND IN WHICH THE RESULTING POLYMER IS COMPLETELY INSOLUBLE AND HEATING SAID SUSPENSION TO A TEMPERATURE WITHIN THE RANGE OF 60 TO 180*C. FOR 3 TO 15 HOURS IN THE PRESENCE OF 0.05 TO 1.0% BY WEIGHT OF A DI-HYDROCARBON SILOXANE SILICONE OIL HAVING A VISCOSITY OF 50 TO 1500 CENTISTOKES, BASED ON THE WEIGHT OF LACTIDE, AND 0.1 TO 1.0 PART BY WEIGHT PER 100 PARTS OF STARTING MATERIAL OF A HALIDE OF A METAL SELECTED FROM THE GROUP CONSISTING OF METALS FROM GROUPS I, II, IV, V, VI AND VII OF THE PERIODIC SYSTEM OF ELEMENTS, WHILE CONTINUOUSLY STIRRING THE SUSPENSION.
References Cited (Backward Citations)
US2486993A
Cited
US2703316A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-09-06 | 1964-03-07 | 1964-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-09-06 | 1968-03-07 | 1968-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-09-06 | 1972-03-07 | 1972-09-06 | $7700.00 | Window Closed / Lapsed |