Patent US2618633A successfully refreshed from Google Patents.
US2618633A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of carboxyethyl cellulose
Assignee: Hercules Powder Co
•
Filing: 1949-12-23
•
Granted: 1952-11-18
•
Expires: 1969-12-23
Abstract
No abstract record available.
Inventors
- 👤 Charles L P Vaughan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 02:48
CPC Classifications
C; C08; C08B; C08B11/00; C08B11/02; C08B11/04; C08B11/10; C08B11/12; Y; Y10; Y10S; Y10S8/00; Y10S8/13
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
69 words
THE PROCESS OF PREPARING A CARBOXYETHYL ETHER OF CELLULOSE, SAID ETHER BEING CHARACTERIZED BY ITS ABILITY TO YIELD CLEAR SOLUTIONS WHEN DISSOLVED IN WATER, WHICH COMPRISES REACTING A SUSPENSION OF ALKALI CELLULOSE IN AN INERT ORGANIC SOLVENT WITH FROM ABOUT 0.5 TO ABOUT 4 MOLES OF ACRYLAMIDE PER ANHYDROGLUCOSE UNIT AT A TEMPERATURE OF ABOUT 70* C. TO ABOUT 95* C. IN THE PRESENCE OF A STRONGLY ALKALINE HYDROXIDE.
References Cited (Backward Citations)
US2338631A
Cited
US2362900A
Cited
US2398767A
Cited
US2517577A
Cited
US2512338A
Cited
US2539417A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-11-18 | 1956-05-19 | 1956-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-11-18 | 1960-05-19 | 1960-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-11-18 | 1964-05-19 | 1964-11-18 | $7700.00 | Window Closed / Lapsed |