Patent US3709780A successfully refreshed from Google Patents.
US3709780A
Expired / Lapsed
US
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Process and product for making paper products of improved dry strength
Assignee: Calgon Corp
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Filing: 1971-11-04
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Granted: 1973-01-09
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Expires: 1991-11-04
Abstract
Abstract PAPER PRODUCTS EXHIBITING MARKEDLY IMPROVED DRY STRENGTH PROPERTIES ARE PRODUCED BY ADDING TO THE CELLULOSE PAPER DISPERSION A CHITIN-BASED COMPOUND COMPRISING A GRAFT COPOLYMER OF 2-ACRYLAMINDO-2-METHYLPROPANE SULFONIC ACID ONTO A CHITOSAN SUBSTRATE.
Inventors
- 👤 R Slagel
- 👤 Marco Sinkovitz G Di
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:36
CPC Classifications
D; D21; D21H; D21H17/00; D21H17/20; D21H17/21; D21H17/24; C; C08; C08F; C08F251/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |