Patent US4784157A successfully refreshed from Google Patents.
US3220918A
Expired / Lapsed
US
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Incombustible board containing mineral and cellulosic fibers and metal oxide and method therefor
Assignee: Domtar Inc
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Filing: 1961-07-28
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Granted: 1965-11-30
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Expires: 1981-07-28
Abstract
No abstract record available.
Inventors
- 👤 Shisko Walter Steven
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 02:33
CPC Classifications
C; C04; C04B; C04B9/00; C08; C08L; C08L2201/00; C08L2201/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
63 words
AN INCOMBUSTIABLE FIBROUS BOARD CONTAINING A MIXTURE OF CELLULOSIC AND MINERAL FIBERS AND AN OXIDE OF ONE OF METALS OF THE GROUP CONSISTING OF MAGNESIUM, ZINC AND CALCIUM, SAID CELLULOSIC FIBERS BEING PRESENT IN THE AMOUNT OF 25 TO 75% OF THE TOTAL FIBERS AND SAID OXIDE BEING PRESENT IN THE AMOUNT OF 40 TO 20% OF THE TOTAL WEIGHT OF THE FIBERS.
Claim 2
Dependent Claim
68 words
A PROCESS OF MAKING AN INCOMBUSTIBLE MOULDED FIBROUS BOARD COMPRISING FORMING A SLURRY OF CELLULOSIC AND MINERAL FIBERS, WHEREIN CELLULOSIC FIBERS CONSTITUTE 25% TO 75% OF THE TOTAL FIBERS, ADDING TO THE SLURRY AN OXIDE OF A METAL OF THE GROUP CONSISTING OF MAGNESIUM, CALCIUM AND ZINC IN AN AMOUNT BETWEEN 40% AND 200% OF THE WEIGHT OF THE TOTAL FIBERS AND FORMING A BOARD FROM SAID SLURRY.
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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) | 1968-11-29 | 1969-05-31 | 1969-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-11-29 | 1973-05-31 | 1973-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-11-29 | 1977-05-31 | 1977-11-30 | $7700.00 | Window Closed / Lapsed |