US2694060A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of bleaching cellulose esters with chlorites
Assignee: Hercules Powder Co
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Filing: 1951-05-17
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Granted: 1954-11-09
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Expires: 1971-05-17
Abstract
No abstract record available.
Inventors
- 👤 Vernon R Grassie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:56
CPC Classifications
C; C08; C08B; C08B3/00; C08B3/22
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
100 words
THE METHOD FOR IMPROVING THE THERMAL COLOR STABILITY OF A CELLULOSE ESTER PREPARED IN THE PRESENCE OF A SULFURIC ACID CATALYST AND CONTAINING COMBINED SULFATE GROUPS WHICH COMPRISES FORMING A WATER SLURRY OF SAID SULFATE-CONTAINING CELLULOSE ESTER, SAID SLURRY CONTAINING FROM 7 TO 15% CELLULOSE ESTER, ADJUSTING THE PH OF SAID SLURRY TO WITHIN THE RANGE OF 3 TO 6, INTRODUCING TO SAID SLURRY FROM 0.001 TO 0.015 PART OF AN ALKALI METAL CHLORITE PER PART OF CELLULOSE ESTER, AND BLEACHING SAID CELLULOSE ESTER AT A TEMPERATURE OF 75* TO 130* C. FOR A PERIOD OF 0.5 TO 6 HOURS.
Claim 2
Independent Claim
100 words
THE METHOD FOR IMPROVING THE THERMAL COLOR STABILITY OF A CELLULOSE ESTER PREPARED IN THE PRESENCE OF A SULFURIC ACID CATALYST AND CONTAINING COMBINED SULFATE GROUPS WHICH COMPRISES FORMING A WATER SLURRY OF SAID SULFATE-CONTAINING CELLULOSE ESTER, SAID SLURRY CONTAINING FROM 7 TO 15% CELLULOSE ESTER, ADJUSTING THE PH OF SAID SLURRY TO WITHIN THE RANGE OF 3 TO 6, INTRODUCING TO SAID SLURRY FROM 0.001 TO 0.015 PART OF AN ALKALI METAL CHLORITE PER PART OF CELLULOSE ESTER, AND BLEACHING SAID CELLULOSE ESTER AT A TEMPERATURE OF 75* TO 130* C. FOR A PERIOD OF 0.5 TO 6 HOURS.
References Cited (Backward Citations)
US2194956A
Cited
US2430674A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-11-08 | 1958-05-10 | 1958-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-11-08 | 1962-05-10 | 1962-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-11-08 | 1966-05-10 | 1966-11-09 | $7700.00 | Window Closed / Lapsed |