US4562050A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing boron nitride
Assignee: YUKAMELAMIN COMPANY Ltd
•
Filing: 1984-08-13
•
Granted: 1985-12-31
•
Expires: 2004-08-13
Abstract
Abstract A process for producing boron nitride is described, comprising reacting at least one boron compound selected from the group consisting of boric acid and metal salt thereof and at least one nitrogen-containing compound which is capable of bonding to the boron compound to form a compound in which a boron atom and a nitrogen atom co-exist, and then heating the compound thus formed at a temperature of at least 600° C. in an atmosphere of inert or reducing gas. This process can produce high purity boron nitride at relatively low temperatures in high yields. Moreover, boron nitride can be obtained in desired crystal forms including a flake-like crystal form.
Inventors
- 👤 Kikuo Koeda
- 👤 Chikara Ito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:58
CPC Classifications
C; C01; C01B; C01B21/00; C01B21/06; C01B21/064; C01P; C01P2002/00; C01P2002/80; C01P2002/88; C01P2004/00; C01P2004/01; C01P2004/03; C01P2004/10; C01P2004/54; C01P2004/60; C01P2004/61
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
178 words
A process for producing boron nitride in a needle-like or filament-like crystal form having a diameter of from 0.1 to 15 μm and a length of from 5 to 150 μm which comprises reacting at least one boron compound selected from the group consisting of boric anhydride, boric acid and a metal salt of boric acid and at least one nitrogen-containing compound selected from the group consisting of urea, melamine, melam, melen, melon, dicyandiamide, ammelide, guanamines and salts of said nitrogen containing compounds in the presence of a solvent to form an addition product as a reaction product, the solvent being one which is capable of causing the reaction product to separate in needle-like or filament-like crystal form and being selected from the group consisting of alcohols, ketones, esters, alcohol esters, amides, aliphatic hydrocarbons, aromatic hydrocarbons, ketone esters, ketone alcohols and ether alcohols, separating the resulting compound from the solvent and thereafter heating the resulting compound in said needle-like or filament-like form at a temperature of at least 600° C. in an atomphere of inert or reducing gas.
Claim 2
Dependent Claim
178 words
A process for producing boron nitride in a needle-like or filament-like crystal form having a diameter of from 0.1 to 15 μm and a length of from 5 to 150 μm which comprises reacting at least one boron compound selected from the group consisting of boric anhydride, boric acid and a metal salt of boric acid and at least one nitrogen-containing compound selected from the group consisting of urea, melamine, melam, melen, melon, dicyandiamide, ammelide, guanamines and salts of said nitrogen containing compounds in the presence of a solvent to form an addition product as a reaction product, the solvent being one which is capable of causing the reaction product to separate in needle-like or filament-like crystal form and being selected from the group consisting of alcohols, ketones, esters, alcohol esters, amides, aliphatic hydrocarbons, aromatic hydrocarbons, ketone esters, ketone alcohols and ether alcohols, separating the resulting compound from the solvent and thereafter heating the resulting compound in said needle-like or filament-like form at a temperature of at least 600° C. in an atomphere of inert or reducing gas.
Claim 3
Dependent Claim
13 words
The process as claimed in claim 1, wherein the nitrogen-containing compound is melamine.
Claim 4
Dependent Claim
12 words
The process as claimed in claim 1, wherein the solvent is acetone.
Claim 5
Dependent Claim
11 words
The process according to claim 2, wherein the solvent is acetone.
Claim 6
Dependent Claim
162 words
A process for producing boron nitride in a needle-like or filament-like crystal form having a diameter of from 0.1 to 15 μm and a length of from 5 to 150 μm which comprises reacting at least one boron compound selected from the group consisting of boric anhydride, boric acid and a metal salt of boric acid and at least one nitrogen-containing compound selected from the group consisting of urea, melamine, melam, melem, melon, dicyanodiamide, ammelide, guanamines and salts of the foregoing nitrogen compounds in the presence of solvent medium, separating the resulting compound from the solvent medium to obtain a needle-like or filament-like crystal form of the resulting compound, thereafter heating the resulting compound in said crystal form at a temperature of at least 600° C. in an atmosphere of inert or reducing gas, wherein the solvent medium is a mixture of water and hydrophilic solvent and the hydrophilic solvent is present in amount sufficient to cause formation of said crystal form.
Claim 7
Dependent Claim
162 words
A process for producing boron nitride in a needle-like or filament-like crystal form having a diameter of from 0.1 to 15 μm and a length of from 5 to 150 μm which comprises reacting at least one boron compound selected from the group consisting of boric anhydride, boric acid and a metal salt of boric acid and at least one nitrogen-containing compound selected from the group consisting of urea, melamine, melam, melem, melon, dicyanodiamide, ammelide, guanamines and salts of the foregoing nitrogen compounds in the presence of solvent medium, separating the resulting compound from the solvent medium to obtain a needle-like or filament-like crystal form of the resulting compound, thereafter heating the resulting compound in said crystal form at a temperature of at least 600° C. in an atmosphere of inert or reducing gas, wherein the solvent medium is a mixture of water and hydrophilic solvent and the hydrophilic solvent is present in amount sufficient to cause formation of said crystal form.
Claim 8
Dependent Claim
17 words
The process according to claim 5 where the solvent is a mixture of water and an alcohol.
Claim 9
Dependent Claim
108 words
A process for producing boron nitride in a needle-like or filament-like crystal form having a diameter of from 0.1 to 15 μm and a length of from 5 to 150 μm which comprises reacting at least one boron compound selected from the group consisting of boric anhydride, boric acide and a metal salt of boric acid and melem in the presence of water, separating the resulting compound from the water to obtain a needle-like or filament-like crystal form of the resulting compound and thereafter heating the resulting compound in said crystal form at a temperature of a least 600° C. in an atmosphere of inert or reducing gas.
Claim 10
Dependent Claim
108 words
A process for producing boron nitride in a needle-like or filament-like crystal form having a diameter of from 0.1 to 15 μm and a length of from 5 to 150 μm which comprises reacting at least one boron compound selected from the group consisting of boric anhydride, boric acide and a metal salt of boric acid and melem in the presence of water, separating the resulting compound from the water to obtain a needle-like or filament-like crystal form of the resulting compound and thereafter heating the resulting compound in said crystal form at a temperature of a least 600° C. in an atmosphere of inert or reducing gas.
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) | 1988-12-30 | 1989-07-01 | 1989-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-30 | 1993-07-01 | 1993-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-30 | 1997-07-01 | 1997-12-31 | $7700.00 | Window Closed / Lapsed |