US3284441A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of preparing carboxymethyl-cellulose
Assignee: Hercules LLC
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Filing: 1965-07-26
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Granted: 1966-11-08
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Expires: 1985-07-26
Abstract
No abstract record available.
Inventors
- 👤 Robert Granville Bishop
- 👤 William Reed Simons
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:34
CPC Classifications
C; C08; C08B; C08B1/00; C08B1/08; C08B11/00; C08B11/02; C08B11/04; C08B11/10; C08B11/12
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
83 words
A SLURRY PROCESS OF PREPARING WATER-SOLUBLE CARBOXYMETHYLCELLULOSE HAVING A D.S OF 0.25-0.75 THAT IS VERY UNIFORMLY SUBSTITUTED AND WHICH IN SOLUTION HAS SUBSTANTIALLY IMPROVED SALT TOLERANCE, WHICH COMPRISES PREPARING ALKALI CELLULOSE, THE ALKALI/CELLULOSE WEIGHT RATIO RANGE IN THE ALKALI CELLULOSE PERIOD BEING 0.4/1.0-2.0/1.0 REDUCING THE AMOUNT OF ALKALI TO AN ALKALI/CELLULOSE WEIGHT RATIO RANGE OF ZERO/1.0-0.25/1.0 IN EXCESS OF THAT WEIGHT WILL BE CHEMICALLY CONSUMED DURING THE ETHERIFICATION, AND THEN ETHERIFYING THE ALKALI CELLULOSE IN THE PRESENCE OF SAID REDUCED AMOUNT OF ALKALI.
Claim 2
Dependent Claim
83 words
A SLURRY PROCESS OF PREPARING WATER-SOLUBLE CARBOXYMETHYLCELLULOSE HAVING A D.S OF 0.25-0.75 THAT IS VERY UNIFORMLY SUBSTITUTED AND WHICH IN SOLUTION HAS SUBSTANTIALLY IMPROVED SALT TOLERANCE, WHICH COMPRISES PREPARING ALKALI CELLULOSE, THE ALKALI/CELLULOSE WEIGHT RATIO RANGE IN THE ALKALI CELLULOSE PERIOD BEING 0.4/1.0-2.0/1.0 REDUCING THE AMOUNT OF ALKALI TO AN ALKALI/CELLULOSE WEIGHT RATIO RANGE OF ZERO/1.0-0.25/1.0 IN EXCESS OF THAT WEIGHT WILL BE CHEMICALLY CONSUMED DURING THE ETHERIFICATION, AND THEN ETHERIFYING THE ALKALI CELLULOSE IN THE PRESENCE OF SAID REDUCED AMOUNT OF ALKALI.
References Cited (Backward Citations)
US2517577A
Cited
US3131176A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-11-07 | 1970-05-09 | 1970-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-11-07 | 1974-05-09 | 1974-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-11-07 | 1978-05-09 | 1978-11-08 | $7700.00 | Window Closed / Lapsed |