Patent US3075963A successfully refreshed from Google Patents.
US3075963A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparing cellulose derivative sulfates
Assignee: Eastman Kodak Co
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Filing: 1960-09-16
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Granted: 1963-01-29
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Expires: 1980-09-16
Abstract
No abstract record available.
Inventors
- 👤 Gordon D Hiatt
- 👤 Martin E Rowley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:43
CPC Classifications
C; C08; C08B; C08B7/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
109 words
A METHOD OF PREPARING A SULFATED CELLULOSE COMPOUND WHICH COMPRISES REACTING UPON A CELLULOSE MATERIAL HAVING FREE AND ESTERIFIABLE HYDROXYL GROUPS SELECTED FROM THE GROUP CONSISTING OF CELLULOSE AND HYDROLYZED LOWER FATTY ACID ESTERS OF CELLULOSE WITH AN ESTERIFICATION BATH COMPRISING ACETIC ANHYDRIDE, ACETYL SULFURIC ACID AND A SALT OF ACETYL SULFURIC ACID, IN THE MAKING OF WHICH ESTERIFICATION BATH AN EXCESS OF 3.5 TO 27 PARTS OF H2SO4 PER 100 PARTS OF THE CELLULOSE OF THE MATERIAL BEING ESTERIED IS SUPPLIED OVER THAT WHICH IS EQUIMOLAR TO THE ALKALI METAL SALT USED IN ITS PREPARATION, AT A TEMPERATURE OF 50-120*. F. UNTIL A WATER SOLUBLE PRODUCT IS OBTAINED.
Claim 2
Independent Claim
109 words
A METHOD OF PREPARING A SULFATED CELLULOSE COMPOUND WHICH COMPRISES REACTING UPON A CELLULOSE MATERIAL HAVING FREE AND ESTERIFIABLE HYDROXYL GROUPS SELECTED FROM THE GROUP CONSISTING OF CELLULOSE AND HYDROLYZED LOWER FATTY ACID ESTERS OF CELLULOSE WITH AN ESTERIFICATION BATH COMPRISING ACETIC ANHYDRIDE, ACETYL SULFURIC ACID AND A SALT OF ACETYL SULFURIC ACID, IN THE MAKING OF WHICH ESTERIFICATION BATH AN EXCESS OF 3.5 TO 27 PARTS OF H2SO4 PER 100 PARTS OF THE CELLULOSE OF THE MATERIAL BEING ESTERIED IS SUPPLIED OVER THAT WHICH IS EQUIMOLAR TO THE ALKALI METAL SALT USED IN ITS PREPARATION, AT A TEMPERATURE OF 50-120*. F. UNTIL A WATER SOLUBLE PRODUCT IS OBTAINED.
References Cited (Backward Citations)
US2143332A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1966-01-28 | 1966-07-30 | 1967-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-01-28 | 1970-07-30 | 1971-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-01-28 | 1974-07-30 | 1975-01-29 | $7700.00 | Window Closed / Lapsed |