US4668590A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ceramic fiber moldings
Assignee: Isolite Babcock Refractories Co Ltd
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Filing: 1986-10-06
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Granted: 1987-05-26
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Expires: 2006-10-06
Abstract
Abstract A process for producing an improved ceramic fiber molding by submersing the molding into a suspension containing colloidal silica and/or colloidal alumina and chromium oxide powder. The chromium oxide is deposited onto the ceramic fibers thereby increasing the molding's resistance to linear shrinkage and corrosion when subjected to high temperatures.
Inventors
- 👤 Masafumi Yamamoto
- 👤 Tatsuo Fukuzaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:47
CPC Classifications
C; C04; C04B; C04B30/00; C04B30/02; C04B2111/00; C04B2111/34
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
170 words
An improved ceramic molded article resistant to thermal shrinkage and corrosion consisting essentially of alumina-silica fibers and binder having chromium oxide in solid solution with the alumina of the fibers, the solid solution of the chromium oxide with the alumina of the fibers being resistant to evaporation of the chromium oxide on exposure to high temperatures, produced (a) by dipping an alumina-silica fiber molding into an aqueous suspension containing at least one colloidal material selected from the group of colloidal silica and colloidal alumina, the colloidal material being present in an amount of 0.2 to 1.0 weight percent of solids based on the weight of water of the suspension, the molding including 10 to 50 weight percent of chromium oxide powder based on the weight of the undipped alumina-silica molding, said chromium oxide powder having a diameter smaller than 62 microns and being present in an amount less than 30 percent based on the weight of the water in the suspension, and then (b) drying the dipped alumina-silica fiber molding.
Claim 2
Dependent Claim
170 words
An improved ceramic molded article resistant to thermal shrinkage and corrosion consisting essentially of alumina-silica fibers and binder having chromium oxide in solid solution with the alumina of the fibers, the solid solution of the chromium oxide with the alumina of the fibers being resistant to evaporation of the chromium oxide on exposure to high temperatures, produced (a) by dipping an alumina-silica fiber molding into an aqueous suspension containing at least one colloidal material selected from the group of colloidal silica and colloidal alumina, the colloidal material being present in an amount of 0.2 to 1.0 weight percent of solids based on the weight of water of the suspension, the molding including 10 to 50 weight percent of chromium oxide powder based on the weight of the undipped alumina-silica molding, said chromium oxide powder having a diameter smaller than 62 microns and being present in an amount less than 30 percent based on the weight of the water in the suspension, and then (b) drying the dipped alumina-silica fiber molding.
Claim 3
Dependent Claim
25 words
The article of claim 1 wherein linear shrinkage is in the range of about 0.6 to 0.9% on heating to 1400° C. for 24 hours.
Claim 4
Dependent Claim
12 words
The article of claim 1 wherein the binder consists of colloidal alumina.
References Cited (Backward Citations)
US4312911A
Cited
US4379111A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-05-25 | 1990-11-24 | 1991-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-25 | 1994-11-24 | 1995-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-25 | 1998-11-24 | 1999-05-26 | $7700.00 | Window Closed / Lapsed |