| 摘要 |
PURPOSE: To obtain low-crystalline and highly purified hexagonal boron nitride (hBN) powder. CONSTITUTION: This hexagonal boron nitride powder has >=5 graphitized index (GI-value) by a powder X-ray diffraction method and contains <=1.0wt.% oxygen. In producing this powder by heating and holding a raw material mixture of a boron source compound containing boron and oxygen and a nitrogen source compound containing nitrogen and/or a reducing agent at >=1600 deg.C in a nitrogen gas atmosphere, the reaction is performed in such a state that a nitrogen gas in a supplying ratio of 1-200L/min in a normal state to 1kg of the raw material mixture and/or a gas generating a nitrogen gas at the above-mentioned temperature is circulated so as to be brought into contact with the raw material mixture. |
