US4287164A
Expired / Lapsed
US
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Process for producing cubic system boron nitride
Assignee: National Institute for Materials Science
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Filing: 1979-10-12
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Granted: 1981-09-01
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Expires: 1999-10-12
Abstract
Abstract A process for producing cubic system boron nitride comprises contacting calcium or strontium boron nitride with hexagonal system boron nitride and heating at higher than 1,450° C. under the thermodynamically stable pressure for cubic system boron nitride.
Inventors
- 👤 Tadashi Endo
- 👤 Osamu Fukunaga
- 👤 Minoru Iwata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:24
CPC Classifications
B; B01; B01J; B01J3/00; B01J3/06; B01J3/062; C; C01; C01B; C01B35/00; C01B35/08; C01B35/14; C01B35/146; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/583; C04B35/5831; B01J2203/00; B01J2203/06; B01J2203/0605; B01J2203/0645; B01J2203/065; B01J2203/066; B01J2203/0675; B01J2203/068
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
38 words
A process for producing cubic system boron nitride which comprises contacting calcium or strontium boron nitride with hexagonal system boron nitride and heating at higher than 1,450° C. under the thermodynamically stable pressure for cubic system boron nitride.
Claim 2
Dependent Claim
38 words
A process for producing cubic system boron nitride which comprises contacting calcium or strontium boron nitride with hexagonal system boron nitride and heating at higher than 1,450° C. under the thermodynamically stable pressure for cubic system boron nitride.
Claim 3
Dependent Claim
22 words
A process according to claim 1 wherein the thermodynamically stable pressure for cubic system is ranging from 40 to 100 k. bar.
Claim 4
Dependent Claim
34 words
A process according to claim 1 wherein the conversion from hexagonal system boron nitride into cubic system boron nitride is carried out in a furnace at a temperature ranging from 1,450° to 2,000° C.
Claim 5
Dependent Claim
23 words
A process according to claim 1 or 3 wherein the conversion is carried out in a container made of hexagonal system boron nitride.
Claim 6
Dependent Claim
22 words
A process according to claim 1 or 3 wherein the conversion is carried out in a container made of a calcined pyrophyllite.
Claim 7
Dependent Claim
24 words
A process according to claim 1 wherein a disk or a plug made of alumina, pyrophyllite, sodium chloride is used for forming a container.
Claim 8
Dependent Claim
29 words
A process according to claim 1 wherein calcium boron nitride is Ca 3 B 2 N 4 and strontium boron nitride is Sr 3 B 2 N 4 .
References Cited (Backward Citations)
US2947617A
Cited
JPS5239599A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-08-31 | 1985-03-02 | 1985-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-31 | 1989-03-02 | 1989-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-31 | 1993-03-02 | 1993-09-01 | $7700.00 | Window Closed / Lapsed |