US4500504A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing silicon carbide whiskers
Assignee: Tokai Carbon Co Ltd
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Filing: 1983-01-25
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Granted: 1985-02-19
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Expires: 2003-01-25
Abstract
Abstract The process according to the present invention involves mixing 100 parts by weight of a silica gel, containing 6.0 to 25.0% by weight with respect to a silicon of a water-soluble compound of at least one metal selected from the group consisting of iron, nickel and cobalt, with 110 to 400 parts by weight of furnace carbon black having a structure indicated by a DBP absorption number of 50 ml/100 g or higher, and then reacting the mixture under a non-oxidative atmosphere at a temperature of 1,300 DEG to 1,700 DEG C. to produce silicon carbide whiskers.
Inventors
- 👤 Akira Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:26
CPC Classifications
C; C30; C30B; C30B25/00; C30B25/005; C30B29/00; C30B29/10; C30B29/36
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
95 words
A process for preparing silicon carbide whiskers comprising mixing 100 parts by weight of a silica gel, containing 6.0 to 25.0% by weight with respect to a silicon of a water-soluble compound of at least one metal selected from the group consisting of iron, nickel and cobalt, with 110 to 400 parts by weight of a furnace carbon black having a structure indicated by a DBP absorption number of not lower than 50 ml/100 g, and reacting the resultant mixture by heating at a temperature ranging from 1,300° to 1,700° C. in a non-oxidizing atmosphere.
Claim 2
Dependent Claim
95 words
A process for preparing silicon carbide whiskers comprising mixing 100 parts by weight of a silica gel, containing 6.0 to 25.0% by weight with respect to a silicon of a water-soluble compound of at least one metal selected from the group consisting of iron, nickel and cobalt, with 110 to 400 parts by weight of a furnace carbon black having a structure indicated by a DBP absorption number of not lower than 50 ml/100 g, and reacting the resultant mixture by heating at a temperature ranging from 1,300° to 1,700° C. in a non-oxidizing atmosphere.
Claim 3
Dependent Claim
38 words
A process according to claim 1, wherein 80 to 200% by weight with respect to the silica gel of sodium chloride is further added as a material for forming a space for production of the silicon carbide whiskers.
Claim 4
Dependent Claim
62 words
A process according to claim 1, wherein the silica gel to be used is one obtainable by immersing a silica gel fine powder having a particle size of not larger than 150 mesh in an aqueous solution of a chloride or nitrate of at least one metal selected from the group consisting of iron, nickel and cobalt, and drying the silica gel.
Claim 5
Dependent Claim
62 words
A process according to claim 2, wherein the silica gel to be used is one obtainable by immersing a silica gel fine powder having a particle size of not larger than 150 mesh in an aqueous solution of a chloride or nitrate of at least one metal selected from the group consisting of iron, nickel and cobalt, and drying the silica gel.
Claim 6
Dependent Claim
46 words
A process according to claim 1, wherein the silica gel which is to contain the water-soluble compound therein is silicic acid containing an SiO 2 component of 99.5% and having a fine porous structure with a surface area of not less than 450 m 2 /g.
Claim 7
Dependent Claim
46 words
A process according to claim 2, wherein the silica gel which is to contain the water-soluble compound therein is silicic acid containing an SiO 2 component of 99.5% and having a fine porous structure with a surface area of not less than 450 m 2 /g.
Claim 8
Dependent Claim
32 words
A process according to claim 1, wherein the silica gel which is to contain the water-soluble compound therein is a synthetic silica gel obtainable by decomposing sodium silicate with an inorganic acid.
Claim 9
Dependent Claim
32 words
A process according to claim 2, wherein the silica gel which is to contain the water-soluble compound therein is a synthetic silica gel obtainable by decomposing sodium silicate with an inorganic acid.
Claim 10
Dependent Claim
30 words
A process according to claim 1, wherein a remaining unreacted carbonaceous source of a reaction product is removed by heating in air at a temperature of at least 550° C.
Claim 11
Dependent Claim
30 words
A process according to claim 2, wherein a remaining unreacted carbonaceous source of a reaction product is removed by heating in air at a temperature of at least 550° C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-19 | 1988-08-20 | 1989-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-19 | 1992-08-20 | 1993-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-19 | 1996-08-20 | 1997-02-19 | $7700.00 | Window Closed / Lapsed |