Patent US1433881A successfully refreshed from Google Patents.
US2826500A
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US
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Use of cationic-modified urea-formaldehyde resins in the manufacture of wet strengthpaper
Assignee: Hercules Powder Co
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Filing: 1954-12-30
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Granted: 1958-03-11
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Expires: 1974-12-30
Abstract
No abstract record available.
Inventors
- 👤 Gerald I Keim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 00:59
CPC Classifications
D; D21; D21H; D21H17/00; D21H17/20; D21H17/33; D21H17/46; D21H17/47; D21H17/49
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
88 words
A WET STRENGTH PAPER COMPRISING A WEB OF CELLULOSIC FIBERS HAVING INCORPORATED THEREWITH FROM 0.1% TO ABOUT 15% BY WEIGHT, BASED ON THE WEIGHT OF THE FIBERS, OF A PARTIALLY POLYMERIZED, HYDROPHILIC, CATIONIC TETRAHYDRO TRIAZONE MODIFIED, UREA-FORMALDEHYDE RESIN, SAID RESIN BEING A REACTION PRODUCT OF UREA, FROM ABOUT 1.8 TO ABOUT 2.4 MOLES OF FORMALDEHYDE PER MOLE OF UREA AND FROM ABOUT 10% TO ABOUT 100% BY WEIGHT, BASED ON THE WEIGHT OF UREA, OF A TETRAHYDROTRIAZONE COMPOUND SELECTED FROM THE CLASS CONSISTING OF COMPOUNDS OF THE FORMUAL
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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) | 1961-03-10 | 1961-09-09 | 1962-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-03-10 | 1965-09-09 | 1966-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-03-10 | 1969-09-09 | 1970-03-11 | $7700.00 | Window Closed / Lapsed |