US4985378A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Carbon-containing refractory and a manufacturing method therefor
Assignee: Shinagawa Refractories Co Ltd
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Filing: 1988-09-06
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Granted: 1991-01-15
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Expires: 2008-09-06
Abstract
Abstract A carbon-containing refractory is formed by mixing 1-10 weight % of silicon nitride, 1-35 weight % of carbon, and a remainder of a refractory raw material, molding the mixture into a molded body, and burning the molded body such that fine whiskers of silicon carbide are uniformly distributed within the matrix.
Inventors
- 👤 Kenji Ichikawa
- 👤 Noboru Tsukamoto
- 👤 Eishi Iida
- 👤 Yuji Yoshimura
- 👤 Junichi Inoue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 01:43
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/653; C04B35/657; C04B35/01; C04B35/10; C04B35/64; C04B35/71; C04B35/78; C04B35/80
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
107 words
A method for preparing a carbon-containing refractory comprising: (i) mixing 1-10 weight % of silicon nitride, 1-35 weight % of carbon, and a remainder of a refractory raw material selected from the group consisting of sintered alumina, electrofused alumina, synthetic mullite, clay minerals, fused silica, zirconia sand, stabilized zirconia, zirconia mullite, alumina zirconia, and quartzite to form a mixture; (ii) molding said mixture into a molded body; and (iii) burning said molded body in a non-oxidizing atmosphere having a nitrogen partial pressure of at most 0.2 atmospheres at a temperature of at least 1300° C., to obtain fine whiskers of silicon carbide uniformly distributed within said refractory.
Claim 2
Independent Claim
107 words
A method for preparing a carbon-containing refractory comprising: (i) mixing 1-10 weight % of silicon nitride, 1-35 weight % of carbon, and a remainder of a refractory raw material selected from the group consisting of sintered alumina, electrofused alumina, synthetic mullite, clay minerals, fused silica, zirconia sand, stabilized zirconia, zirconia mullite, alumina zirconia, and quartzite to form a mixture; (ii) molding said mixture into a molded body; and (iii) burning said molded body in a non-oxidizing atmosphere having a nitrogen partial pressure of at most 0.2 atmospheres at a temperature of at least 1300° C., to obtain fine whiskers of silicon carbide uniformly distributed within said refractory.
Claim 3
Dependent Claim
33 words
The method of claim 1, wherein in said mixing, said silicon nitride is present in an amount of 3-8 weight % and said carbon is present in an amount of 5-30 weight %.
Claim 4
Dependent Claim
33 words
The method of claim 1, wherein in said mixing, said silicon nitride is present in an amount of 4-8 weight % and said carbon is present in an amount of 10-20 weight %.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-01-14 | 1994-07-16 | 1995-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-14 | 1998-07-16 | 1999-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-01-14 | 2002-07-16 | 2003-01-15 | $7700.00 | Window Closed / Lapsed |