US3278520A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydroxypropyl cellulose and process
Assignee: Hercules LLC
•
Filing: 1963-02-08
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Granted: 1966-10-11
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Expires: 1983-02-08
Abstract
No abstract record available.
Inventors
- 👤 Eugene D Klug
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:55
CPC Classifications
C; C08; C08B; C08B11/00; C08B11/20; C08B1/00; C08B1/08; C08B11/02; C08B11/04; C08B11/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
86 words
A PROCESS OF PREPARING HYDROXYPROLYL CELLULOSE COMPRISING MIXING AT A TEMPERATURE OF ABOUT 0* C. -35* C. CELLULOSIC MATERIAL, ALKALI AND WATER IN THE PRESENCE OF LIQUID PROPYLENE OXIDE AS A DILUENT, AND THEN ALLOWING PROPYLENE OXIDE TO REACT AT A TEMPERATURE OF ABOUT 65* C.150* C. WITH THE ALKALI CELLILOSE UNTIL THE HYDROXYPROPYL CELLULOSE BEING PRODUCES REACHES AN MS OF AT LEAST 2, THE ALKALI/CELLULOSE RATIO BEING 0.02-0.5, THE WATER CELLULOSE RATIO BEING 0.1-4 AND 0.1-2 IN THE ALKALI CELLULOSE PERIOD AND ETHERIFICATION PERIOD, RESPECTIVELY.
Claim 2
Dependent Claim
86 words
A PROCESS OF PREPARING HYDROXYPROLYL CELLULOSE COMPRISING MIXING AT A TEMPERATURE OF ABOUT 0* C. -35* C. CELLULOSIC MATERIAL, ALKALI AND WATER IN THE PRESENCE OF LIQUID PROPYLENE OXIDE AS A DILUENT, AND THEN ALLOWING PROPYLENE OXIDE TO REACT AT A TEMPERATURE OF ABOUT 65* C.150* C. WITH THE ALKALI CELLILOSE UNTIL THE HYDROXYPROPYL CELLULOSE BEING PRODUCES REACHES AN MS OF AT LEAST 2, THE ALKALI/CELLULOSE RATIO BEING 0.02-0.5, THE WATER CELLULOSE RATIO BEING 0.1-4 AND 0.1-2 IN THE ALKALI CELLULOSE PERIOD AND ETHERIFICATION PERIOD, RESPECTIVELY.
References Cited (Backward Citations)
US2667481A
Cited
US2572039A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-10-10 | 1970-04-11 | 1970-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-10-10 | 1974-04-11 | 1974-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-10-10 | 1978-04-11 | 1978-10-11 | $7700.00 | Window Closed / Lapsed |