US3020197A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for production of high brightness high strength wood pulps
Assignee: Honeywell International Inc
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Filing: 1960-08-05
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Granted: 1962-02-06
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Expires: 1980-08-05
Abstract
No abstract record available.
Inventors
- 👤 Schuber John
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:21
CPC Classifications
D; D21; D21C; D21C9/00; D21C9/10; D21C9/1057
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
175 words
A STAGED PROCESS FOR THE PRODUCTION OF SUPERBLEACHED CELLULOSIC MATERIAL HAVING A BRIGHTNESS IN EXCESS OF 90 AND OF HIGH STRENGTH CHARACTERISTICS WHICH COMPRISES, IN THE SEQUENCE SPECIFIED, (A) TREATING AN AQUEOUS SUSPENSION OF UNBLEACHED CELLULOSIC MATERIAL CONTAINING A SUBSTANTIAL AMOUNT OF LIGNEOUS AND NONCELLULOSIC COLOR-FORMING IMPURITIES IN A FIRST STAGE WITH ELEMENTAL CHLORINE AT NOT GREATER THAN PH 6 FOR NOT IN EXCESS OF 90 MINUTES TO CHLORINATE A MAJOR PORTION OF SAID TREATING THE CELLULOSIC MATERIAL AT A CONSISTENCY OF ABOUT 9-17% WITH AN ALKALINE HYPOCHLORITE IN A SECOND STAGE AT GREATER THAN PH 8 FOR NOT IN EXCESS OF 240 MINUTES TO OXIDIZE A PORTION OF THE RESIDUAL LIGNEOUS AND COLORFORMING IMPURITIES TO BRIGHTEN THE PULP WITHOUT MATERIAL DEGRATION OF THE CELLULOSE, WATER WASHING THE CELLULOSIC MATERIAL, (C) TREATING THE CELLULOSIC MATERIAL AT A CONSISTENCY OF ABOUT 9%-17% IN A THIRD STAGE WITH CHLORINE DIOXIDE AT NOT GREATER THAN PH 6.5 FOR NOT IN EXCESS OF 300 MINUTES TO OXIDIZE AN ADDITIONAL PORTION OF SAID RESIDUAL IMPURITIES WITHOUT MATERIAL DEGRADATION OF THE
Claim 2
Dependent Claim
175 words
A STAGED PROCESS FOR THE PRODUCTION OF SUPERBLEACHED CELLULOSIC MATERIAL HAVING A BRIGHTNESS IN EXCESS OF 90 AND OF HIGH STRENGTH CHARACTERISTICS WHICH COMPRISES, IN THE SEQUENCE SPECIFIED, (A) TREATING AN AQUEOUS SUSPENSION OF UNBLEACHED CELLULOSIC MATERIAL CONTAINING A SUBSTANTIAL AMOUNT OF LIGNEOUS AND NONCELLULOSIC COLOR-FORMING IMPURITIES IN A FIRST STAGE WITH ELEMENTAL CHLORINE AT NOT GREATER THAN PH 6 FOR NOT IN EXCESS OF 90 MINUTES TO CHLORINATE A MAJOR PORTION OF SAID TREATING THE CELLULOSIC MATERIAL AT A CONSISTENCY OF ABOUT 9-17% WITH AN ALKALINE HYPOCHLORITE IN A SECOND STAGE AT GREATER THAN PH 8 FOR NOT IN EXCESS OF 240 MINUTES TO OXIDIZE A PORTION OF THE RESIDUAL LIGNEOUS AND COLORFORMING IMPURITIES TO BRIGHTEN THE PULP WITHOUT MATERIAL DEGRATION OF THE CELLULOSE, WATER WASHING THE CELLULOSIC MATERIAL, (C) TREATING THE CELLULOSIC MATERIAL AT A CONSISTENCY OF ABOUT 9%-17% IN A THIRD STAGE WITH CHLORINE DIOXIDE AT NOT GREATER THAN PH 6.5 FOR NOT IN EXCESS OF 300 MINUTES TO OXIDIZE AN ADDITIONAL PORTION OF SAID RESIDUAL IMPURITIES WITHOUT MATERIAL DEGRADATION OF THE
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) | 1965-02-05 | 1965-08-07 | 1966-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-02-05 | 1969-08-07 | 1970-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-02-05 | 1973-08-07 | 1974-02-06 | $7700.00 | Window Closed / Lapsed |