Patent US3341516A successfully refreshed from Google Patents.
US3341516A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Surface-sulfonated cellulose ethers having improved water dispersibility
Assignee: Dow Chemical Co
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Filing: 1964-05-04
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Granted: 1967-09-12
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Expires: 1984-05-04
Abstract
No abstract record available.
Inventors
- 👤 Savage Albert Buckley
- 👤 Julius C Aldrich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:54
CPC Classifications
C; C08; C08B; C08B11/00; C08B11/20; C08B13/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
101 words
A PROCESS WHICH COMPRISES THE STEPS OF PASSING SULFUR TRIOXIDE VAPOR THROUGH A DRY, WATER-SOLUBLE PARTICULATE, NON-IONIC CELLULOSE ETHER CONTAINING LESS THAN ABOUT 6 PERCENT BY WEIGHT FREE MOISTURE, BASED ON THE WEIGHT OF THE CELLULOSE ETHER, SAID CELLULOSE ETHER BEING SOLUBLE IN WATER AT A PH OF 7 TO 10, AND THEREAFTER PASSING AMMONIA GAS THROUGH THE CELLULOSE ETHER TO EFFECT NEUTRALIZATION OF SULFONIC MOIETIES WITHIN THE CELLULOSE ETHER MASS TO PRODUCE A D.S. OF SULFONATE SUBSTITUTION ALONG THE ETHER CHAIN WITHIN THE RANGE FROM ABOUT 0.001 TO ABOUT 0.1 WHEREBY THE WATER DISPERSIBILITY OF THE CELLULOSE ETHER IS ENHANCED.
Claim 2
Dependent Claim
101 words
A PROCESS WHICH COMPRISES THE STEPS OF PASSING SULFUR TRIOXIDE VAPOR THROUGH A DRY, WATER-SOLUBLE PARTICULATE, NON-IONIC CELLULOSE ETHER CONTAINING LESS THAN ABOUT 6 PERCENT BY WEIGHT FREE MOISTURE, BASED ON THE WEIGHT OF THE CELLULOSE ETHER, SAID CELLULOSE ETHER BEING SOLUBLE IN WATER AT A PH OF 7 TO 10, AND THEREAFTER PASSING AMMONIA GAS THROUGH THE CELLULOSE ETHER TO EFFECT NEUTRALIZATION OF SULFONIC MOIETIES WITHIN THE CELLULOSE ETHER MASS TO PRODUCE A D.S. OF SULFONATE SUBSTITUTION ALONG THE ETHER CHAIN WITHIN THE RANGE FROM ABOUT 0.001 TO ABOUT 0.1 WHEREBY THE WATER DISPERSIBILITY OF THE CELLULOSE ETHER IS ENHANCED.
References Cited (Backward Citations)
US3257380A
Cited
US3280102A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-09-11 | 1971-03-13 | 1971-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-09-11 | 1975-03-13 | 1975-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-09-11 | 1979-03-13 | 1979-09-12 | $7700.00 | Window Closed / Lapsed |