US4812298A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing sialon powders
Assignee: Ube Corp
•
Filing: 1986-09-23
•
Granted: 1989-03-14
•
Expires: 2006-09-23
Abstract
Abstract Uniform sialon powders having a sharp particle size distribution are obtained by mixing (i) amorphous silicon nitride powders, (ii) an oxygen-containing compound of silicon or/and aluminum, and (iii) aluminum metal, aluminum nitride and/or silicon, and then heating the resultant mixture at 1300 DEG to 1800 DEG C. in an atmosphere containing nitrogen.
Inventors
- 👤 Yasuhiko Kohtoku
- 👤 Teturo Kunisawa
- 👤 Takuji Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:48
CPC Classifications
C; C01; C01B; C01B21/00; C01B21/082; C01B21/0821; C01B21/0826
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
121 words
A method for producing a crystalline sialon powder, comprising the steps of: (a) mixing the following components in a composition for a desired sialon: (i) an amorphous silicon nitride powder, (ii) an oxygen-containing compound of silicon and/or aluminum, and (iii) aluminum metal, aluminum nitride and/or silicon; said components being selected in kind and in amount to produce a sialon of the formula Si 6-Z Al Z O Z N 8-Z where Z is a number greater than 0 and up to 4.2, and then (b) heating the resultant mixture at a temperature in a range of 1300° C. to 1800° C. in a nitrogen-containing atmosphere to obtain crystallized sialon powder having primary particles in the range of 0.2 to 2 μm.
Claim 2
Independent Claim
121 words
A method for producing a crystalline sialon powder, comprising the steps of: (a) mixing the following components in a composition for a desired sialon: (i) an amorphous silicon nitride powder, (ii) an oxygen-containing compound of silicon and/or aluminum, and (iii) aluminum metal, aluminum nitride and/or silicon; said components being selected in kind and in amount to produce a sialon of the formula Si 6-Z Al Z O Z N 8-Z where Z is a number greater than 0 and up to 4.2, and then (b) heating the resultant mixture at a temperature in a range of 1300° C. to 1800° C. in a nitrogen-containing atmosphere to obtain crystallized sialon powder having primary particles in the range of 0.2 to 2 μm.
Claim 3
Dependent Claim
38 words
A method according to claim 1, wherein said amorphous silicon nitride powder is produced by reacting silicon tetrahalide with ammonia and heating the resultant reaction product at a temperature in a range of 300° C. to 1300° C.
Claim 4
Dependent Claim
15 words
A method according to claim 1, wherein said oxygen-containing compound of silicon is amorphous silica.
Claim 5
Dependent Claim
14 words
A method according to claim 1, wherein said oxygen-containing compound of aluminum is γ-alumina.
Claim 6
Dependent Claim
20 words
A method according to claim 1, wherein said oxygen-containing compound of aluminum and/or silicon are in the form of powders.
Claim 7
Dependent Claim
20 words
A method according to claim 1, wherein said aluminum metal, aluminum nitride and/or silicon are in the form of powders.
Claim 8
Dependent Claim
35 words
A method according to claim 1, wherein said mixture of said components (i), (ii) and (iii) is obtained by heating a mixture of a precursor of said ingredient (i) and said components (ii) and (iii).
Claim 9
Dependent Claim
20 words
A method according to claim 1, wherein said nitrogen-containing atmosphere consists of nitrogen, ammonia, or a mixture of argon therewith.
References Cited (Backward Citations)
US3991166A
Cited
US3991148A
Cited
US4127416A
Cited
US4127416B1
Cited
US4147759A
Cited
US4323323A
Cited
US4360506A
Cited
JPS5678472A
Cited
US4438051A
Cited
US4506020A
Cited
US4499193A
Cited
US4499193B1
Cited
JPS59199581A
Cited
US4552711A
Cited
JPS60191064A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-03-13 | 1992-09-12 | 1993-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-13 | 1996-09-12 | 1997-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-13 | 2000-09-12 | 2001-03-14 | $7700.00 | Window Closed / Lapsed |