US4264565A
Expired / Lapsed
US
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Method for producing powder of α-silicon nitride
Assignee: Toshiba Corp
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Filing: 1980-02-13
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Granted: 1981-04-28
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Expires: 2000-02-13
Abstract
Abstract A method for producing powder of α-silicon nitride which comprises the steps of: adding 0.3 to 2 parts by weight of powder of carbon and 0.005 to 1 paret by weight of at least one silicon compound selected from the group consisting of Si 3 N 4 , SiC and silicon oxide nitride series compounds to one part by weight (as converted to SiO 2 ) to a liquid silane derivative which produces a precipitate and HCl by hydrolysis and further causes SiO 2 to be grown by the baking of said precipitate, or the precipitate produced by hydrolysis of the liquid silane derivatives; hydrolyzing the resultant mixture, if necessary; washing the mixture to separate a solid component, if necessary; and baking the solid component for reduction and nitrogenization at a temperature of 1300° to 1500° C. in an atmosphere mainly consisting of a nitrogen gas or a gas of a nitrogen compound.
Inventors
- 👤 Hiroshi Inoue
- 👤 Katsutoshi Komeya
- 👤 Akihiko Tsuge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:49
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C01; C01B; C01B21/00; C01B21/06; C01B21/068; C01B21/0685; C01P; C01P2004/00; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/80
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
139 words
A method for producing powder of α-silicon nitride which comprises the steps of: adding 0.3 to 2 parts by weight of powder of carbon and 0.005 to 1 part by weight of at least one silicon compound selected from the group consisting of Si 3 N 4 , SiC and Si 2 ON 2 to one part by weight, when converted to SiO 2 of a liquid alkylchlorosilane that forms a precipitate and HCl by hydrolysis which precipitate is convertible to SiO 2 at a baking temperature of 1300° to 1500° C.; hydrolyzing the resultant mixture; washing the mixture to separate a solid component; and baking the solid component at a temperature of 1300° to 1500° C. in an atmosphere mainly consisting of a nitrogen gs or a gas of a nitrogen compound to effect formation of α-silicon nitride.
Claim 2
Independent Claim
139 words
A method for producing powder of α-silicon nitride which comprises the steps of: adding 0.3 to 2 parts by weight of powder of carbon and 0.005 to 1 part by weight of at least one silicon compound selected from the group consisting of Si 3 N 4 , SiC and Si 2 ON 2 to one part by weight, when converted to SiO 2 of a liquid alkylchlorosilane that forms a precipitate and HCl by hydrolysis which precipitate is convertible to SiO 2 at a baking temperature of 1300° to 1500° C.; hydrolyzing the resultant mixture; washing the mixture to separate a solid component; and baking the solid component at a temperature of 1300° to 1500° C. in an atmosphere mainly consisting of a nitrogen gs or a gas of a nitrogen compound to effect formation of α-silicon nitride.
Claim 3
Independent Claim
140 words
A method for producing powder of α-silicon nitride which comprises the steps of: hydrolyzing a liquid alkylchlorosilane that forms a precipitate and HCl by hydrolysis, which precipitate is convertible to SiO 2 at a baking temperature of 1300° to 1500° C.; washing the hydrolyzed mass to separate a solid component; adding 0.3 to 2 parts by weight of powder of carbon and 0.005 to 1 part by weight of at least one silicon compound selected from the group consisting of Si 3 N 4 , SiC and Si 2 ON 2 to 1 part by weight when converted to SiO 2 of said solid component; and baking the resultant mixture at a temperature of 1300° to 1500° C. in an atmosphere mainly consisting of a nitrogen gas or a gas of a nitrogen compound to effect formation of α-silicon nitride.
Claim 4
Independent Claim
140 words
A method for producing powder of α-silicon nitride which comprises the steps of: hydrolyzing a liquid alkylchlorosilane that forms a precipitate and HCl by hydrolysis, which precipitate is convertible to SiO 2 at a baking temperature of 1300° to 1500° C.; washing the hydrolyzed mass to separate a solid component; adding 0.3 to 2 parts by weight of powder of carbon and 0.005 to 1 part by weight of at least one silicon compound selected from the group consisting of Si 3 N 4 , SiC and Si 2 ON 2 to 1 part by weight when converted to SiO 2 of said solid component; and baking the resultant mixture at a temperature of 1300° to 1500° C. in an atmosphere mainly consisting of a nitrogen gas or a gas of a nitrogen compound to effect formation of α-silicon nitride.
Claim 5
Dependent Claim
13 words
The method according to claim 1 or 2, wherein the alkylchlorosilane is methyltrichlorosilane.
Claim 6
Dependent Claim
18 words
The method according to claim 1 or 2, wherein the alkylchlorosilane is a mixture of methyltrichlorosilane and dimethyldichlorosilane.
Claim 7
Dependent Claim
17 words
The method according to claim 1 or 2, wherein the nitrogen compound gas is NH 3 .
Claim 8
Dependent Claim
33 words
The method according to claim 1 or 2, wherein the solid component is thermally dehydrated at a temperature of 200° to 300° C., before heat-treated at a temperature of 1300° to 1500° C.
Claim 9
Dependent Claim
36 words
The method according to claim 1 or 2, wherein the reaction product heat-treated at a temperature of 1300° to 1500° C. is again heat-treated in an oxidizing atmosphere at a temperature of 600° to 800° C.
Claim 10
Dependent Claim
26 words
The method according to claim 1 or 2, wherein the powder of carbon is added in an amount ranging from 0.4 to 1 part by weight.
Claim 11
Dependent Claim
28 words
The method according to claim 1 or 2, wherein the powder of the silicon compound is added in an amount ranging from 0.01 to 0.1 part by weight.
Claim 12
Dependent Claim
22 words
The method according to claim 1 or 2, wherein the powder of carbon has a mean particle size smaller than 1 micron.
Claim 13
Dependent Claim
24 words
The method according to claim 1 or 2, wherein the powder of the silicon compound has a mean particle size smaller than 2 microns.
References Cited (Backward Citations)
US3855385A
Cited
US4117095A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-04-27 | 1984-10-27 | 1985-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-27 | 1988-10-27 | 1989-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-27 | 1992-10-27 | 1993-04-28 | $7700.00 | Window Closed / Lapsed |