| 摘要 |
PURPOSE:To manufacture easily boron nitride or a substance contg. boron nitride by heating zinc borate or a mixture capable of forming zinc borate in a flow of gas contg. ammonia. CONSTITUTION:Zinc borate having preferably a composition represented by a formula 2ZnO.3B2O3.nH2O (where n=3.5, 7.5 or 8.5) or a mixture capable of forming zinc borate is heated to >=650 deg.C in a flow of gas contg. ammonia to obtain a substance contg. boron nitride. A mixture of boron nitride with zinc oxide formed by heating zinc borate at about 650-700 deg.C is heated to >=700 deg.C in a flow of gas contg. ammonia or other reducing gas such as hydrogen, CO or methane to remove the zinc oxide by reduction and volatilization, so boron nitride can be obtd. This boron nitride or said substance contg. boron nitride can be converted into a sintered body of high quality by compression under heating or by heating in a restrained state. |
