Patent US2801938A successfully refreshed from Google Patents.
US2801938A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treating paper with silica sol, and product produced
Assignee: EIDP Inc
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Filing: 1953-05-12
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Granted: 1957-08-06
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Expires: 1973-05-12
Abstract
No abstract record available.
Inventors
- 👤 Ralph K Iler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:05
CPC Classifications
D; D21; D21H; D21H17/00; D21H17/63; D21H17/67; D21H17/68; Y; Y10; Y10T; Y10T428/00; Y10T428/26; Y10T428/268
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
77 words
IN A PROCESS FOR TREATING FIBROUS CELLULOSIC PAPER THE STEPS COMPRISING IMPREGNATING THE PAPER WITH AN AQUEOUS COLLOIDAL SILICA SOL CONTAINING COMBINED SODIUM IN A SILICA: NA2O WEIGHT RATIO OF ABOUT FROM 10:1 TO 100:1 AND IN WHIHC THE SILICA PARTICLES HAVE AN ULTIMATE PARTICLES SIZE OF ABOUT FROM 10 TO 30 MILLIMICRONS AND EVAPORATING THE SOL TO DRYNESS IN CONTACT WITH THE PAPER , WHEREBY THE SILICA IS IRREVERSIBLY ATTACHED TO THE FIBERS OF THE PAPER.
Claim 2
Dependent Claim
77 words
IN A PROCESS FOR TREATING FIBROUS CELLULOSIC PAPER THE STEPS COMPRISING IMPREGNATING THE PAPER WITH AN AQUEOUS COLLOIDAL SILICA SOL CONTAINING COMBINED SODIUM IN A SILICA: NA2O WEIGHT RATIO OF ABOUT FROM 10:1 TO 100:1 AND IN WHIHC THE SILICA PARTICLES HAVE AN ULTIMATE PARTICLES SIZE OF ABOUT FROM 10 TO 30 MILLIMICRONS AND EVAPORATING THE SOL TO DRYNESS IN CONTACT WITH THE PAPER , WHEREBY THE SILICA IS IRREVERSIBLY ATTACHED TO THE FIBERS OF THE PAPER.
References Cited (Backward Citations)
US2577485A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-08-05 | 1961-02-04 | 1961-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-08-05 | 1965-02-04 | 1965-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-08-05 | 1969-02-04 | 1969-08-06 | $7700.00 | Window Closed / Lapsed |