US4746480A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for providing a protective oxide coating on ceramic fibers
Assignee: CNA Holdings LLC
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Filing: 1986-08-11
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Granted: 1988-05-24
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Expires: 2006-08-11
Abstract
Abstract Thermally stable ceramic fibers are provided by pyrolysis of organosilicon preceramic polymeric fibers to ceramic form and contacting the ceramic fibers with an oxygen-containing gas so as to oxidize the surface of the fibers and form an in-situ oxide coating.
Inventors
- 👤 Terence J. Clark
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 03:40
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B35/00; C04B35/622; C04B35/62227; C04B41/45; C04B41/4584
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
71 words
A process for improving the thermal stability of ceramic fibers by providing a protective oxide coating on said ceramic fibers comprising: forming a ceramic fiber by pyrolyzing a fiber spun from a polysilazane preceramic polymer and after pyrolysis heat treating said ceramic fiber in an inert gas containing 10 ppm to 10,000 ppm as O 2 of an oxygen-containing gas to form an in situ oxide coating on said ceramic fiber.
Claim 2
Dependent Claim
71 words
A process for improving the thermal stability of ceramic fibers by providing a protective oxide coating on said ceramic fibers comprising: forming a ceramic fiber by pyrolyzing a fiber spun from a polysilazane preceramic polymer and after pyrolysis heat treating said ceramic fiber in an inert gas containing 10 ppm to 10,000 ppm as O 2 of an oxygen-containing gas to form an in situ oxide coating on said ceramic fiber.
Claim 3
Dependent Claim
16 words
The process of claim 1 wherein said oxygen-containing gas comprises air or pure O 2 .
Claim 4
Dependent Claim
18 words
The process of claim 1 wherein said polysilazane is a hydridopolysilazane polymer formed by reacting trichlorosilane with hexamethyldisilazane.
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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) | 1991-05-24 | 1991-11-23 | 1992-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-24 | 1995-11-23 | 1996-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-24 | 1999-11-23 | 2000-05-24 | $7700.00 | Window Closed / Lapsed |