US2882120A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of bleaching chemical wood pulp with nitrogen trichloride
Assignee: Champion Paper and Fibre Co
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Filing: 1955-02-25
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Granted: 1959-04-14
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Expires: 1975-02-25
Abstract
No abstract record available.
Inventors
- 👤 Jr William B Stoddard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:09
CPC Classifications
D; D21; D21C; D21C9/00; D21C9/10; D21C9/12
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
83 words
IN THE PROCESS OF BLEACHING CHEMICAL WOOD PULP, THE IMPROVEMENT WHICH COMPRISES APPLYING NITROGEN TRICHLORIDE TO CHEMICAL WOOD PULP IN THE PRESENCE OF A QUANTITY OF WATER AT LEAST EQUAL IN WEIGHT TO THE DRY WEIGHT OF THE PULP, IN THE ABSENCE OF FREE CHLORINE AND AT A PH IN THE RANGE OF 1.0 TO 4.5 OBTAINED BY THE ADDITION OF A NONOXIDIZING ACID, THE PERIOD OF CONTACT BETWEEN THE NITROGEN TRICHLORIDE AND THE PULP BEING SUFFICIENT TO PERMIT BLEACHING TO BE EFFECTED.
Claim 2
Dependent Claim
83 words
IN THE PROCESS OF BLEACHING CHEMICAL WOOD PULP, THE IMPROVEMENT WHICH COMPRISES APPLYING NITROGEN TRICHLORIDE TO CHEMICAL WOOD PULP IN THE PRESENCE OF A QUANTITY OF WATER AT LEAST EQUAL IN WEIGHT TO THE DRY WEIGHT OF THE PULP, IN THE ABSENCE OF FREE CHLORINE AND AT A PH IN THE RANGE OF 1.0 TO 4.5 OBTAINED BY THE ADDITION OF A NONOXIDIZING ACID, THE PERIOD OF CONTACT BETWEEN THE NITROGEN TRICHLORIDE AND THE PULP BEING SUFFICIENT TO PERMIT BLEACHING TO BE EFFECTED.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-04-13 | 1962-10-13 | 1963-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-04-13 | 1966-10-13 | 1967-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-04-13 | 1970-10-13 | 1971-04-14 | $7700.00 | Window Closed / Lapsed |