Patent US4068848A successfully refreshed from Google Patents.
Patent US4226841A successfully refreshed from Google Patents.
US4226841A
Expired / Lapsed
US
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Method of producing silicon carbide powder
Assignee: Toshiba Corp
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Filing: 1979-03-07
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Granted: 1980-10-07
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Expires: 1999-03-07
Abstract
Abstract A method of producing a silicon carbide powder consisting of fine particles of uniform shape and size, comprising baking at 1,350° to 1,850° C. under a non-oxidizing atmosphere a powdery mixture consisting of 1 part by weight of silica powder or a compound forming silica powder at high temperatures, carbon powder or a compound forming carbon powder at high temperatures, and silicon carbide or a substance forming silicon carbide at high temperatures, the amounts of the silica powder-forming compounds, the carbon powder-forming compounds and the silicon carbide powder-forming substance being determined such that the amounts of the formed powders are equal to those specified above.
Inventors
- 👤 Katsutoshi Komeya
- 👤 Hiroshi Inoue
- 👤 Haruo Kudo
- 👤 Hiroshi Endo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:16
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/565; C01; C01B; C01B32/00; C01B32/90; C01B32/914; C01B32/956; C01B32/963; C01B32/97; C01P; C01P2004/00; C01P2004/01; C01P2004/03; C01P2004/51; C01P2004/52; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/80
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
133 words
A method of producing a silicon carbide powder, comprising, forming a powerdery mixture consisting of 1 part by weight of silica powder or a compound forming silica powder at the baking temperature employed, 0.5 to 4 parts by weight of carbon powder or a compound forming carbon powder at said baking temperature, and 0.05 to 1 part by weight of silicon carbide powder, the amounts of the silica powder-forming compound, and the carbon powder-forming compound being such that the amounts of the formed silica and carbon powders are equal to those specified above and baking said mixture at 1350° C. to 1850° C. under a non-oxidizing atmosphere selected from the group consisting of carbon monoxide, argon and hydrogen to produce a silicon carbide powder consisting of fine particles of uniform size and shape.
Claim 2
Independent Claim
133 words
A method of producing a silicon carbide powder, comprising, forming a powerdery mixture consisting of 1 part by weight of silica powder or a compound forming silica powder at the baking temperature employed, 0.5 to 4 parts by weight of carbon powder or a compound forming carbon powder at said baking temperature, and 0.05 to 1 part by weight of silicon carbide powder, the amounts of the silica powder-forming compound, and the carbon powder-forming compound being such that the amounts of the formed silica and carbon powders are equal to those specified above and baking said mixture at 1350° C. to 1850° C. under a non-oxidizing atmosphere selected from the group consisting of carbon monoxide, argon and hydrogen to produce a silicon carbide powder consisting of fine particles of uniform size and shape.
Claim 3
Dependent Claim
18 words
The method according to claim 1, wherein the baking is carried out at 1,400° C. to 1,700° C.
Claim 4
Independent Claim
131 words
A method of producing a silicon carbide powder, comprising forming a powdery mixture consisting of 1 part by weight of silica powder or a compound forming silica powder at the baking temperature employed, 0.5 to 4 parts by weight of carbon powder or a compound forming carbon powder at said baking temperature, and 0.05 to 1 part by weight of silicon carbide powder, the amounts of the silica powder-forming compound, and the carbon powder-forming compound being such that the amounts of the formed silica and carbon powders are equal to those specified above and baking said mixture at a temperature exceeding 1,550° C. under a non-oxidizing atmosphere selected from the group consisting of nitrogen and ammonia to produce a silicon carbide powder consisting of fine particles of uniform size and shape.
Claim 5
Independent Claim
131 words
A method of producing a silicon carbide powder, comprising forming a powdery mixture consisting of 1 part by weight of silica powder or a compound forming silica powder at the baking temperature employed, 0.5 to 4 parts by weight of carbon powder or a compound forming carbon powder at said baking temperature, and 0.05 to 1 part by weight of silicon carbide powder, the amounts of the silica powder-forming compound, and the carbon powder-forming compound being such that the amounts of the formed silica and carbon powders are equal to those specified above and baking said mixture at a temperature exceeding 1,550° C. under a non-oxidizing atmosphere selected from the group consisting of nitrogen and ammonia to produce a silicon carbide powder consisting of fine particles of uniform size and shape.
Claim 6
Dependent Claim
44 words
The method according to claim 1 or 3, wherein the amounts of carbon powder and silicon carbide powder range between 0.6 and 2 parts by weight and between 0.1 and 1 part by weight, respectively, relative to 1 part by weight of silica powder.
Claim 7
Dependent Claim
32 words
The method according to claim 1 or 3, wherein the average particle size of the silica powder, carbon powder and silicon carbide powder contained in the powdery mixture is at most 0.5μ.
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) | 1983-10-07 | 1984-04-07 | 1984-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-07 | 1988-04-07 | 1988-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-07 | 1992-04-07 | 1992-10-07 | $7700.00 | Window Closed / Lapsed |