Patent US4172108A successfully refreshed from Google Patents.
US4172108A
Expired / Lapsed
US
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Process for production of sialons
Assignee: Sumitomo Chemical Co Ltd
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Filing: 1977-12-14
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Granted: 1979-10-23
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Expires: 1997-12-14
Abstract
Abstract Sialon, which is one of promising materials in the field of engineering ceramics, is prepared by mixing a silicon nitride precursor such as amino- or imino-silanes and an alumina precursor such as trialkoxy- or triacyloxy-aluminums or polyaluminoxanes to obtain a sialon precursor, and then heating the sialon precursor at a temperature of not lower than 1000 DEG C. either in an ammonium or inert gas atmosphere or under reduced pressures.
Inventors
- 👤 Takayoshi Maeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:01
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/597; C01; C01B; C01B21/00; C01B21/082; C01B21/0821; C01B21/0826
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
124 words
A process for producing sialon, which comprises, mixing a silicon nitride precursor having at least one silicon-nitrogen bond and which is at least one substituted or unsubstituted amino or imino silane and an alumina precursor having at least one aluminum-oxygen bond, is at least one member selected from the group consisting of trailkoxyaluminums, triacyloxyaluminums and polyaluminoxanes in an organic solvent, removing the organic solvent by evaporation to provide a sialon precursor composition, and effecting conversion of the sialon precursor composition into sialon by heating the sialon precursor composition at a temperature of not lower than 1000° C. at a rate of elevating the temperature of at most 400° C. per hour either in an atmosphere of an ammonia or inert gas under reduced pressures.
Claim 2
Dependent Claim
124 words
A process for producing sialon, which comprises, mixing a silicon nitride precursor having at least one silicon-nitrogen bond and which is at least one substituted or unsubstituted amino or imino silane and an alumina precursor having at least one aluminum-oxygen bond, is at least one member selected from the group consisting of trailkoxyaluminums, triacyloxyaluminums and polyaluminoxanes in an organic solvent, removing the organic solvent by evaporation to provide a sialon precursor composition, and effecting conversion of the sialon precursor composition into sialon by heating the sialon precursor composition at a temperature of not lower than 1000° C. at a rate of elevating the temperature of at most 400° C. per hour either in an atmosphere of an ammonia or inert gas under reduced pressures.
Claim 3
Dependent Claim
21 words
A process according to claim 1, wherein the organic solvent is a member selected from ethers, aliphatic hydrocarbons and aromatic hydrocarbons.
Claim 4
Dependent Claim
79 words
A process according to claim 1, wherein the conversion is effected by heating the sialon precursor composition at a temperature of 450° C. to 1100° C. in an atmosphere of an ammonia or inert gas or under reduced pressures to obtain a heat-treated product, grinding the heat-treated product and then heating the resulting powder in an atmosphere of an ammonia or inert gas at a temperature of not lower than 1300° C. to obtain a β'-phase sialon fine powder.
Claim 5
Dependent Claim
78 words
A process according to claim 1, wherein the conversion is effected by calcining the sialon precursor composition at a temperature of 450° to 1400° C. either in an atmosphere of an ammonia or inert gas or under reduced pressures, grinding the calcined product, molding the resulting powder to obtain a green, and then firing the green in an atmosphere of an inert gas at a temperature of not lower than 1300° C. to obtain a sialon article molded.
Claim 6
Dependent Claim
18 words
A process according to claim 4, wherein the molding is carried out by compression molding or hot-press molding.
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) | 1982-10-22 | 1983-04-23 | 1983-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-22 | 1987-04-23 | 1987-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-22 | 1991-04-23 | 1991-10-23 | $7700.00 | Window Closed / Lapsed |