US4382104A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for coating alumina containing refractory fibers with chromium oxide
Assignee: Stemcor Corp
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Filing: 1981-07-06
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Granted: 1983-05-03
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Expires: 2001-07-06
Abstract
Abstract A method for uniformly coating ceramic fibers comprising from about 40 to 100 weight percent aluminum oxide with Cr 2 O 3 . The method comprises precipitating Cr 2 O 3 .xH 2 O (chromium oxide hydrate) upon the fibers followed by converting the Cr 2 O 3 .xH 2 O to Cr 2 O 3 . The resulting Cr 2 O 3 coated fibers have good shrinkage resistance, good temperature resistance and good flexibility in thick fiber articles.
Inventors
- 👤 Russell D. Smith
- 👤 Richard E. Tressler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 04:33
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/62227; C04B35/62231; C03; C03C; C03C13/00; C03C13/006; C03C25/00; C03C25/10; C03C25/42; C04B20/00; C04B20/10; C04B20/1055; C04B41/00; C04B41/45; C04B41/50; C04B41/5025; C04B41/5033; C04B41/80; C04B41/81; C04B41/85; C04B41/87
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
69 words
A method for uniformly coating ceramic fibers comprising from about 40 to 100 weight percent aluminum oxide, the fibers being contained in a mat having a thickness of at least 0.5 centimeters, with Cr 2 O 3 which method comprises precipitating Cr 2 O 3 .xH 2 O upon the fibers followed by converting the precipitated Cr 2 O 3 .xH 2 O to Cr 2 O 3 .
Claim 2
Independent Claim
69 words
A method for uniformly coating ceramic fibers comprising from about 40 to 100 weight percent aluminum oxide, the fibers being contained in a mat having a thickness of at least 0.5 centimeters, with Cr 2 O 3 which method comprises precipitating Cr 2 O 3 .xH 2 O upon the fibers followed by converting the precipitated Cr 2 O 3 .xH 2 O to Cr 2 O 3 .
Claim 3
Independent Claim
141 words
A method for uniformly coating ceramic fibers of a fiber mat having a thickness of from 0.5 to 5.0 centimeters with Cr 2 O 3 , said fibers of said mat comprising from about 40 to 100 weight percent aluminum oxide, which method comprises the following sequence of steps: (1) contacting the fibers of the mat with an aqueous solution containing from about 0.1 to about 7 weight percent of chromium ion; (2) while said fibers are in contact with said solution, raising the pH of the solution to above about 9.5 to precipitate Cr 2 O 3 .xH 2 O upon the fibers; (3) vaporizing the remaining water from the fibers; and (4) heating said fibers to from about 200° to about 1200° C. to convert said Cr 2 O 3 .xH 2 O to Cr 2 O 3 .
Claim 4
Independent Claim
141 words
A method for uniformly coating ceramic fibers of a fiber mat having a thickness of from 0.5 to 5.0 centimeters with Cr 2 O 3 , said fibers of said mat comprising from about 40 to 100 weight percent aluminum oxide, which method comprises the following sequence of steps: (1) contacting the fibers of the mat with an aqueous solution containing from about 0.1 to about 7 weight percent of chromium ion; (2) while said fibers are in contact with said solution, raising the pH of the solution to above about 9.5 to precipitate Cr 2 O 3 .xH 2 O upon the fibers; (3) vaporizing the remaining water from the fibers; and (4) heating said fibers to from about 200° to about 1200° C. to convert said Cr 2 O 3 .xH 2 O to Cr 2 O 3 .
Claim 5
Dependent Claim
11 words
The method of claim 2 wherein the fibers are microcrystalline fibers.
Claim 6
Dependent Claim
20 words
The method of claim 3 wherein the fibers, prior to coating, comprise up to 60 weight percent SiO 2 .
Claim 7
Dependent Claim
18 words
The method of claim 2 wherein said pH is raised by adjusting it upward with NH 4 OH.
Claim 8
Dependent Claim
22 words
The method of claim 2 wherein said solution contains a compound which will thermally decompose to NH 3 or free hydroxyl ion.
Claim 9
Dependent Claim
31 words
The method of claim 6 wherein said compound is urea and the pH is adjusted to above about 9.5 by heating said solution to decompose the urea to NH 3 .
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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) | 1986-05-02 | 1986-11-01 | 1987-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-02 | 1990-11-01 | 1991-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-02 | 1994-11-01 | 1995-05-03 | $7700.00 | Window Closed / Lapsed |