US2916413A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Paper manufacture
Assignee: Hercules Powder Co
•
Filing: 1957-04-15
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Granted: 1959-12-08
•
Expires: 1977-04-15
Abstract
No abstract record available.
Inventors
- 👤 John A Harpham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:56
CPC Classifications
D; D21; D21H; D21H11/00; D21H11/16; D21H11/20
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
75 words
IN THE METHOD FOR FORMING PAPER WHEREIN AN AQUEOUS SUSPENSION OF A FIBROUS MATERIAL IS DEWATERED ON A SCREEN TO FORM A MATTED WEB AND SAID MATTED WEB IS DRIED, THE IMPROVEMENT WHICH COMPRISES EMPLOYING AS A FIBROUS MATERIAL A WATER-INSOLUBLE AND ALKALI-INSOLUBLE HYDROXYALKYL CELLULOSE WHEREBY A PAPER OF IMPROVED STRENGTH IS OBTAINED, SAID CELLULOSE RESULTING FROM ETHERIFYING RAW COTTON LINTERS TO A D.S. NOT IN EXCESS OF ABOUT 0.20 AND THEN CHEMICALLY PURIFYING SAME.
Claim 2
Dependent Claim
75 words
IN THE METHOD FOR FORMING PAPER WHEREIN AN AQUEOUS SUSPENSION OF A FIBROUS MATERIAL IS DEWATERED ON A SCREEN TO FORM A MATTED WEB AND SAID MATTED WEB IS DRIED, THE IMPROVEMENT WHICH COMPRISES EMPLOYING AS A FIBROUS MATERIAL A WATER-INSOLUBLE AND ALKALI-INSOLUBLE HYDROXYALKYL CELLULOSE WHEREBY A PAPER OF IMPROVED STRENGTH IS OBTAINED, SAID CELLULOSE RESULTING FROM ETHERIFYING RAW COTTON LINTERS TO A D.S. NOT IN EXCESS OF ABOUT 0.20 AND THEN CHEMICALLY PURIFYING SAME.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-12-07 | 1963-06-08 | 1963-12-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-12-07 | 1967-06-08 | 1967-12-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-12-07 | 1971-06-08 | 1971-12-08 | $7700.00 | Window Closed / Lapsed |