Patent US2513807A successfully refreshed from Google Patents.
US2513807A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of carboxyalkyl cellulose
Assignee: Hercules Powder Co
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Filing: 1948-06-04
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Granted: 1950-07-04
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Expires: 1968-06-04
Abstract
No abstract record available.
Inventors
- 👤 Bayard T Lamborn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:00
CPC Classifications
C; C08; C08B; C08B11/00; C08B11/02; C08B11/04; C08B11/10; C08B11/12
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
96 words
A PROCESS FOR RECOVERING THE FREE ACID FORM OF CARBOXYALKYLCELLULOSE IN A PURFIED STATE WHICH COMPRISES ADJUSTING THE PH OF A CRUDE ETHERIFICATION REACTION MIXTURE CONTAINING A SALT OF CARBOXYALKYLCELLULOSE, BY-PRODUCT SALTS, RESIDUAL REACTANTS, AND WATER TO A VALUE LESS THAN ABOUT 7; DRYING TO A MOISTURE CONTENT LESS THAN ABOUT 5% BY WEIGHT; TREATING THE DRIED CRUDE REACTION MIXTURE WITH WATER ADJUSTED TO A PH OF LESS THAN ABOUT 3.0 FOR A PERIOD OF TIME SUFFICIENT TO RENDER THE CARBOXYALKYLCELLULOSE INSOLUBLE IN WATER; AND THEREAFTER WASHING THE CARBOXYALKYLCELLULOSE WITH WATER UNTIL FREE OF CONTAMININATING SALTS.
Claim 2
Dependent Claim
96 words
A PROCESS FOR RECOVERING THE FREE ACID FORM OF CARBOXYALKYLCELLULOSE IN A PURFIED STATE WHICH COMPRISES ADJUSTING THE PH OF A CRUDE ETHERIFICATION REACTION MIXTURE CONTAINING A SALT OF CARBOXYALKYLCELLULOSE, BY-PRODUCT SALTS, RESIDUAL REACTANTS, AND WATER TO A VALUE LESS THAN ABOUT 7; DRYING TO A MOISTURE CONTENT LESS THAN ABOUT 5% BY WEIGHT; TREATING THE DRIED CRUDE REACTION MIXTURE WITH WATER ADJUSTED TO A PH OF LESS THAN ABOUT 3.0 FOR A PERIOD OF TIME SUFFICIENT TO RENDER THE CARBOXYALKYLCELLULOSE INSOLUBLE IN WATER; AND THEREAFTER WASHING THE CARBOXYALKYLCELLULOSE WITH WATER UNTIL FREE OF CONTAMININATING SALTS.
References Cited (Backward Citations)
US2178630A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-07-03 | 1954-01-02 | 1954-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-07-03 | 1958-01-02 | 1958-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-07-03 | 1962-01-02 | 1962-07-04 | $7700.00 | Window Closed / Lapsed |