US4551316A
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Process for producing boron nitride of cubic system
Assignee: Resonac Holdings Corp
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Filing: 1982-11-02
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Granted: 1985-11-05
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Expires: 2002-11-02
Abstract
Abstract A boron nitride type compound of the formula: LiMBN 2 where M is calcium or barium and other similar compounds are provided. These compounds are prepared by heating a mixture of (i) finely divided Li 3 N or metallic lithium, (ii) finely divided alkaline earth metal nitride selected from Ca 3 N 2 , Mg 3 N 2 , Sr 3 N 2 , Ba 3 N 2 and Be 3 N 2 , and/or an alkaline earth metal selected from Ca, Mg, Sr, Ba and Be, and (iii) hexagonal boron nitride at 800° to 1,300° C. in an inert gas or ammonia atmosphere thereby to react the ingredients (i), (ii) and (iii) with each other in a molten state, and then, cooling the reaction product to be solidified. The above-mentioned compounds are useful as a catalyst for use in the production of cubic boron nitride from hexagonal boron nitride.
Inventors
- 👤 Eiichi Iizuka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:43
CPC Classifications
C; C01; C01B; C01B35/00; C01B35/08; C01B35/14; C01B35/146; B; B01; B01J; B01J3/00; B01J3/06; B01J3/062; 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: 13
Claim 1
Independent Claim
154 words
A process for producing boron nitride of the cubic system, which comprises the steps of: maintaining a mixture of (i) a finely divided lithium nitride (Li 3 N) or metallic lithium powder, (ii) a finely divided powder of at least one alkaline earth metal nitride or alkaline earth metal selected from the group consisting of calcium nitride (Ca 3 N 2 ), barium nitride (Ba 3 N 2 ), metallic calcium and metallic barium, and (iii) hexagonal boron nitride (BN), at a temperature of 800° to 1,300° C. in an atmosphere of an inert gas or ammonia thereby to react the ingredients (i), (ii) and (iii) with each other in a molten state; cooling the reaction product to be thereby solidified; mixing the reaction product with a hexagonal boron nitride powder; and then, maintaining the thus-obtained mixture in a high-temperature and high-pressure region in which boron nitride of the cubic system is thermodynamically stable.
Claim 2
Dependent Claim
154 words
A process for producing boron nitride of the cubic system, which comprises the steps of: maintaining a mixture of (i) a finely divided lithium nitride (Li 3 N) or metallic lithium powder, (ii) a finely divided powder of at least one alkaline earth metal nitride or alkaline earth metal selected from the group consisting of calcium nitride (Ca 3 N 2 ), barium nitride (Ba 3 N 2 ), metallic calcium and metallic barium, and (iii) hexagonal boron nitride (BN), at a temperature of 800° to 1,300° C. in an atmosphere of an inert gas or ammonia thereby to react the ingredients (i), (ii) and (iii) with each other in a molten state; cooling the reaction product to be thereby solidified; mixing the reaction product with a hexagonal boron nitride powder; and then, maintaining the thus-obtained mixture in a high-temperature and high-pressure region in which boron nitride of the cubic system is thermodynamically stable.
Claim 3
Dependent Claim
42 words
A process according to claim 1 wherein the amounts of the respective ingredient (i), (ii) and (iii) are such that the atomic ratio of the respective elements: lithium, alkaline earth metal, boron and nitrogen in said mixture is (1-1.4):(1-1.4):1:(not more than 2).
Claim 4
Dependent Claim
30 words
A process according to claim 1, wherein 5 to 50 parts by weight of the reaction product is mixed with 100 parts by weight of the hexagonal boron nitride powder.
Claim 5
Dependent Claim
37 words
A process according to claim 1, wherein the mixture of the reaction product with the hexagonal boron nitride powder is maintained at a temperature of 1,300° to 1,600° C. under a pressure of 40 to 60 kbar.
Claim 6
Dependent Claim
25 words
A process according to claim 1, wherein said reaction product comprises a compound represented by the formula: LiMBN 2 wherein M is calcium or barium.
Claim 7
Dependent Claim
160 words
A process for producing boron nitride of the cubic system, which comprises the steps of: maintaining a mixture of (i) a finely divided lithium nitride (Li 3 N) or metallic lithium powder, (ii) a finely divided powder of at least one alkaline earth metal nitride (Ca 3 N 2 ), barium nitride (Ba 3 N 2 ), metallic calcium and metallic barium, and (iii) hexagonal boron nitride (BN), at a temperature of 800° to 1,300° C. in an atomsphere of an inert gas or ammonia thereby to react the ingredients (i), (ii) and (iii) with each other in a molten state to produce a reaction product comprising a compound represented by the formula: LiMBN.sub.2 wherein M is calcium or barium; cooling the reaction product to be thereby solidified; mixing the reaction product with a hexagonal boron nitride powder; and maintaining the thus-obtained mixture in a high-temperature and high-pressure region in which boron nitride of the cubic system is thermodynamically stable.
Claim 8
Dependent Claim
160 words
A process for producing boron nitride of the cubic system, which comprises the steps of: maintaining a mixture of (i) a finely divided lithium nitride (Li 3 N) or metallic lithium powder, (ii) a finely divided powder of at least one alkaline earth metal nitride (Ca 3 N 2 ), barium nitride (Ba 3 N 2 ), metallic calcium and metallic barium, and (iii) hexagonal boron nitride (BN), at a temperature of 800° to 1,300° C. in an atomsphere of an inert gas or ammonia thereby to react the ingredients (i), (ii) and (iii) with each other in a molten state to produce a reaction product comprising a compound represented by the formula: LiMBN.sub.2 wherein M is calcium or barium; cooling the reaction product to be thereby solidified; mixing the reaction product with a hexagonal boron nitride powder; and maintaining the thus-obtained mixture in a high-temperature and high-pressure region in which boron nitride of the cubic system is thermodynamically stable.
Claim 9
Dependent Claim
42 words
A process according to claim 6, wherein the amounts of the respective ingredients (i), (ii) and (iii) are such that the atomic ratio of the respective elements: lithium, alkaline earth metal, boron and nitrogen in said mixture is (1-1.4):(1-1.4):1:(not more than 2).
Claim 10
Dependent Claim
30 words
A process according to claim 6, wherein 5 to 50 parts by weight of the reaction product is mixed with 100 parts by weight of the hexagonal boron nitride powder.
Claim 11
Dependent Claim
36 words
A process according to claim 6, wherein the mixture of the reaction product with the hexagonal boron nitride powder is maintained at a temperature of 1,300° to 1,600° C. under pressure of 40 to 60 kbar.
Claim 12
Dependent Claim
30 words
A process according to claim 7, wherein 5 to 50 parts by weight of the reaction product is mixed with 100 parts by weight of the hexangonal boron nitride powder.
Claim 13
Dependent Claim
36 words
A process according to claim 10, wherein the mixture of the reaction product with the hexagonal boron nitride powder is maintained at a temperature of 1,300° to 1,600° C. under pressure of 40 to 60 kbar.
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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) | 1988-11-04 | 1989-05-06 | 1989-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-04 | 1993-05-06 | 1993-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-04 | 1997-05-06 | 1997-11-05 | $7700.00 | Window Closed / Lapsed |