US2938826A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bleaching of cellulosic pulp
Assignee: AMELIORATION ET LE DEV DES PRO
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Filing: 1958-09-02
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Granted: 1960-05-31
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Expires: 1978-09-02
Abstract
No abstract record available.
Inventors
- 👤 Marpillero Paolo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:17
CPC Classifications
D; D21; D21C; D21C9/00; D21C9/10; D21C9/12; D21C9/14
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
86 words
IN A PROCESS FOR BLEACHING CHEMICAL OR SEMI-CHEMICAL CELLULOSE PULPS, THE IMPROVEMENT WHICH COMPRISES THE STEP OF CONTACTING AN AQUEOUS SUSPENSION OF THE PULP, AT A TEMPERATURE WITHIN THE RANGE OF 20*-80*C., WITH A METALLIC CHLORATE SELECTED FROM THE GROUP CONSISTING OF THE ALKALI METAL CHLORATES AND ALKALINE EARTH METAL CHLORATES, IN THE PRESENCE OF A VANDIUM CATALYST, SAID CHLORATE BEING PRESENT IN AN AMOUNT WITHIN THE RANGE OF 0.2-10% BY WEIGHT OF THE PULP, AND SAID SUSPENSION CONTAINING 1-2 GRAMS ACID PER LITRE OF SUSPENSION.
Claim 2
Dependent Claim
86 words
IN A PROCESS FOR BLEACHING CHEMICAL OR SEMI-CHEMICAL CELLULOSE PULPS, THE IMPROVEMENT WHICH COMPRISES THE STEP OF CONTACTING AN AQUEOUS SUSPENSION OF THE PULP, AT A TEMPERATURE WITHIN THE RANGE OF 20*-80*C., WITH A METALLIC CHLORATE SELECTED FROM THE GROUP CONSISTING OF THE ALKALI METAL CHLORATES AND ALKALINE EARTH METAL CHLORATES, IN THE PRESENCE OF A VANDIUM CATALYST, SAID CHLORATE BEING PRESENT IN AN AMOUNT WITHIN THE RANGE OF 0.2-10% BY WEIGHT OF THE PULP, AND SAID SUSPENSION CONTAINING 1-2 GRAMS ACID PER LITRE OF SUSPENSION.
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) | 1963-05-31 | 1963-11-30 | 1964-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-05-31 | 1967-11-30 | 1968-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-05-31 | 1971-11-30 | 1972-05-31 | $7700.00 | Window Closed / Lapsed |