US4833107A
Expired / Lapsed
US
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Method for producing nitride-base ceramics
Assignee: Tonen General Sekiyu KK
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Filing: 1988-10-04
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Granted: 1989-05-23
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Expires: 2008-10-04
Abstract
Abstract Fired nitride-base ceramics, i.e., silicon nitride or oxynitride, having a low carbon content and, therefore, low electrical and thermal conductivities, can be produced by heat treating a ceramic precursor comprising polysilazane, polysiloxazane or polycarbosilazane or a mixture thereof as the main ingredient in a reducing atmosphere such as hydrogen, ammonia or a gas containing these components, followed by firing.
Inventors
- 👤 Hiroshi Kaya
- 👤 Kozaburo Tamura
- 👤 Takeshi Isoda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:59
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/589
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
89 words
A method for producing a nitride-base ceramic, consisting essentially of the steps of: heat treating a ceramic precursor consisting essentialy of one selected from the group consisting of polysilazane, polysiloxazane, polycarbosilazane and a mixture thereof, in an atmosphere consisting esentially of at least one of hydrogen, ammonia and hydrazine at a temperature within a range of 400° to 1000° C. to reduce the carbon content of the ceramic precursor; and then firing the ceramic precursor to produce one of silicon nitride and silicon oxynitride with a low carbon content.
Claim 2
Independent Claim
89 words
A method for producing a nitride-base ceramic, consisting essentially of the steps of: heat treating a ceramic precursor consisting essentialy of one selected from the group consisting of polysilazane, polysiloxazane, polycarbosilazane and a mixture thereof, in an atmosphere consisting esentially of at least one of hydrogen, ammonia and hydrazine at a temperature within a range of 400° to 1000° C. to reduce the carbon content of the ceramic precursor; and then firing the ceramic precursor to produce one of silicon nitride and silicon oxynitride with a low carbon content.
Claim 3
Dependent Claim
25 words
The method according to claim 1, wherein said heat treatment is carried out at a temperature within a range of 400° C. to 800° C.
Claim 4
Dependent Claim
17 words
The method according to claim 1, wherein the atmosphere for the heat treatment consists essentially of hydrogen.
Claim 5
Dependent Claim
17 words
The method according to claim 1, wherein the atmosphere for the heat treatment consists essentially of ammonia.
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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) | 1992-05-22 | 1992-11-21 | 1993-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-22 | 1996-11-21 | 1997-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-22 | 2000-11-21 | 2001-05-23 | $7700.00 | Window Closed / Lapsed |