Patent US4405589A successfully refreshed from Google Patents.
US4405589A
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Process for producing silicon nitride powder
Assignee: Ube Corp
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Filing: 1982-11-05
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Granted: 1983-09-20
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Expires: 2002-11-05
Abstract
Abstract Silicon nitride powder having a uniform particle size of regular crystals is produced by a process comprising the steps of: (1) reacting (i) at least one compound having the general formula [I] RmSiCl4-m [I] wherein R is an aliphatic residual group having 1 to 4 carbon atoms or an aromatic residual group having 6 to 8 carbon atoms and m is 1, 2, or 3 and (ii) a compound having the general formula [II] HnSiCl4-n [II] wherein n is 0, 1, 2, or 3, the ratio of silicon atoms to carbon atoms (Si/C) in both compounds [I] and [II] being 0.5 to 50 with ammonia and, then, (2) calcining the resultant reaction product in the first step at a temperature of 1200 DEG C. to 1700 DEG C. under an inert or reducing gas atmosphere.
Inventors
- 👤 Tadashi Iwai
- 👤 Takashi Kawahito
- 👤 Tetsuo Yamada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:10
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/589; C01; C01B; C01B21/00; C01B21/06; C01B21/068; C01B21/082; C01B21/087; C01P; C01P2004/00; C01P2004/01; C01P2004/03; C01P2004/30; C01P2004/32; C01P2004/60; C01P2004/61; C01P2004/62; C01P2006/00; C01P2006/10; C01P2006/12
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
126 words
A process for producing silicon nitride powder comprising the steps of: (1) reacting (i) at least one compound having the general formula [I] R.sub.m SiCl.sub.4-m [I] wherein R is an aliphatic residual group having 1 to 4 carbon atoms or an aromatic residual group having 6 to 8 carbon atoms, and m is 1, 2, or 3 and (ii) a compound having the general formula [II] H.sub.n SiCl.sub.4-n [II] wherein n is 0, 1, 2, or 3, the ratio of silicon atom to carbon atom (Si/C) in both compounds [I] and [II] being 0.5 to 50 with ammonia and, then, (2) calcining the resultant reaction product in the first step at a temperature of 1200° C. to 1700° C. under an inert or reducing gas atmosphere.
Claim 2
Dependent Claim
126 words
A process for producing silicon nitride powder comprising the steps of: (1) reacting (i) at least one compound having the general formula [I] R.sub.m SiCl.sub.4-m [I] wherein R is an aliphatic residual group having 1 to 4 carbon atoms or an aromatic residual group having 6 to 8 carbon atoms, and m is 1, 2, or 3 and (ii) a compound having the general formula [II] H.sub.n SiCl.sub.4-n [II] wherein n is 0, 1, 2, or 3, the ratio of silicon atom to carbon atom (Si/C) in both compounds [I] and [II] being 0.5 to 50 with ammonia and, then, (2) calcining the resultant reaction product in the first step at a temperature of 1200° C. to 1700° C. under an inert or reducing gas atmosphere.
Claim 3
Dependent Claim
29 words
A process as claimed in claim 1, wherein the reaction of step (1) is carried out at a temperature of -80° C. to 30° C. in a liquid phase.
Claim 4
Dependent Claim
28 words
A process as claimed in claim 1, wherein the reaction step (1) is carried out at a temperature of 0° C. to 200° C. in a vapor phase.
Claim 5
Dependent Claim
50 words
A process as claimed in claim 1, wherein the reaction of the step (1) is carried out by using ammonia in an amount of at least 2 times of the molecular number based on the atomic number of the chlorine bonded to the silicon in the compounds [I] and [II].
Claim 6
Dependent Claim
156 words
A process for producing silicon nitride powder comprising the steps of: (1) reacting (i) (a) at least one compound selected from the group consisting of trichloromethyl silane, dichlorodimethyl silane, and trichloroethyl silane or (b) a mixture thereof with at least one compound having the general formula R'.sub.n SiCl.sub.4-n [III] wherein R' is an aliphatic residual group having 1 to 4 carbon atoms or an aromatic residual group having 6 to 8 carbon atoms and n is 1, 2, or 3, provided that R' is not a methyl group and an ethyl group in the case of n=1 and that R' is not a methyl group in the case of n=2, the ratio of silicon atoms to carbon atoms (Si/C) in the mixture being 0.5 to 50 with (ii) ammonia and, then, (2) calcining the resultant reaction product in the first step at a temperature of 1200° C. to 1700° C. under an inert or reducing atmosphere.
Claim 7
Dependent Claim
156 words
A process for producing silicon nitride powder comprising the steps of: (1) reacting (i) (a) at least one compound selected from the group consisting of trichloromethyl silane, dichlorodimethyl silane, and trichloroethyl silane or (b) a mixture thereof with at least one compound having the general formula R'.sub.n SiCl.sub.4-n [III] wherein R' is an aliphatic residual group having 1 to 4 carbon atoms or an aromatic residual group having 6 to 8 carbon atoms and n is 1, 2, or 3, provided that R' is not a methyl group and an ethyl group in the case of n=1 and that R' is not a methyl group in the case of n=2, the ratio of silicon atoms to carbon atoms (Si/C) in the mixture being 0.5 to 50 with (ii) ammonia and, then, (2) calcining the resultant reaction product in the first step at a temperature of 1200° C. to 1700° C. under an inert or reducing atmosphere.
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) | 1986-09-19 | 1987-03-21 | 1987-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-19 | 1991-03-21 | 1991-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-19 | 1995-03-21 | 1995-09-20 | $7700.00 | Window Closed / Lapsed |