US4873039A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing shaped articles of ceramics
Assignee: JNC Corp
•
Filing: 1988-02-16
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Granted: 1989-10-10
•
Expires: 2008-02-16
Abstract
Abstract Forming a shaped article of polysilazane, contacting this shaped article with dry ammonia at a temperature of 20°-200° C. to thereby effect infusibilization, and finally subjecting the ammonia-treated product to further heat treatment at a higher temperature in a nitrogen atmosphere to thereby produce a shaped ceramic article.
Inventors
- 👤 Tamio Serita
- 👤 Hiroyuki Takeuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:27
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/589
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
69 words
The method which comprises (a) forming a shaped article of polysilazene, (b) contacting the shaped article of step (a) with dry ammonia while the shaped article is maintained at a temperature within the range of 20°-200° C. to effect infusibilization, and (c) subjecting the ammonia-treated product resulting from step (b) to further heat treatment at a higher temperature in a nitrogen atmosphere to thereby produce a shaped ceramic article.
Claim 2
Independent Claim
69 words
The method which comprises (a) forming a shaped article of polysilazene, (b) contacting the shaped article of step (a) with dry ammonia while the shaped article is maintained at a temperature within the range of 20°-200° C. to effect infusibilization, and (c) subjecting the ammonia-treated product resulting from step (b) to further heat treatment at a higher temperature in a nitrogen atmosphere to thereby produce a shaped ceramic article.
Claim 3
Dependent Claim
13 words
The method according to claim 1 wherein said shaped article is a fiber.
Claim 4
Dependent Claim
28 words
The method according to claim 1 wherein said shaped articles are in the form of fibers produced by the melt-spinning a polysilazane having repeating unit structures of ##STR3##
References Cited (Backward Citations)
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Cited
FR2190764A1
Cited
US3853567A
Cited
US4097294A
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US4172108A
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EP0075826A2
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US4543344A
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EP0200326A1
Cited
US4937828A
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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) | 1992-10-09 | 1993-04-10 | 1993-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-09 | 1997-04-10 | 1997-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-09 | 2001-04-10 | 2001-10-10 | $7700.00 | Window Closed / Lapsed |