US2989519A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bromide as bleaching catalyst
Assignee: International Paper Canada Inc
•
Filing: 1959-04-23
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Granted: 1961-06-20
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Expires: 1979-04-23
Abstract
No abstract record available.
Inventors
- 👤 John H E Herbst
- 👤 Hans A Krassig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:33
CPC Classifications
D; D21; D21C; D21C9/00; D21C9/10; D21C9/1026; D21C9/1036
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
66 words
IN THE ALKALINE HYPOCHLORITE BLEACHING OF CELLULOSIC PULP FOR CONVERSION TO A CELLULOSE DERIVATIVE, THE PROCESS OF INCREASING THE RATE OF REDUCTION OF VISCOSITY OF THE PULP WHICH COMPRISES ADDING TO THE REACTION MIXTURE OF HYPOCHLORITE AND PULP A MATERIAL SELECTED FROM THE GROUP CONSISTING OF ELEMENTAL BROMINE, HYDROBROMIC ACID, HYPOBROMOUS ACID, AND SALTS THEREOF IN AN AMOUNT BETWEEN 0.001% AND 0.10% BASED ON THE PULP.
Claim 2
Dependent Claim
66 words
IN THE ALKALINE HYPOCHLORITE BLEACHING OF CELLULOSIC PULP FOR CONVERSION TO A CELLULOSE DERIVATIVE, THE PROCESS OF INCREASING THE RATE OF REDUCTION OF VISCOSITY OF THE PULP WHICH COMPRISES ADDING TO THE REACTION MIXTURE OF HYPOCHLORITE AND PULP A MATERIAL SELECTED FROM THE GROUP CONSISTING OF ELEMENTAL BROMINE, HYDROBROMIC ACID, HYPOBROMOUS ACID, AND SALTS THEREOF IN AN AMOUNT BETWEEN 0.001% AND 0.10% BASED ON THE PULP.
References Cited (Backward Citations)
US1904406A
Cited
US2587064A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-06-19 | 1964-12-19 | 1965-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-06-19 | 1968-12-19 | 1969-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-06-19 | 1972-12-19 | 1973-06-20 | $7700.00 | Window Closed / Lapsed |