PROBLEM TO BE SOLVED: To provide a hexagonal crystal boron nitride powder having suppressed amount of boron eluted in water not only just after manufacturing but also after long term storage.SOLUTION: There is provided a hexagonal crystal boron nitride powder having a value of a ratio r(=I1/I2), between maximum peak strength I1 of an infrared absorption spectrum appeared in a range of wave number of 815±10 cm-1 and maximum peak strength I2 of the infrared absorption spectrum appeared in a range of wave number of 3420±10 cm-1 of 1000 or more and graphitization index of 3.2 or less.SELECTED DRAWING: NoneCOPYRIGHT: (C)2017,JPO&INPIT【課題】製造直後のみならず長期保管後に至るまで、水に溶出するホウ素の量が抑制された六方晶窒化ホウ素粉末を提供する。【解決手段】波数815±10cm-1の範囲内に出現する赤外吸収スペクトルの最大ピーク強度I1と、波数3420±10cm-1の範囲内に出現する赤外吸収スペクトルの最大ピーク強度I2との比の値r(=I1/I2)が1000以上であり、かつ黒鉛化指数が3.2以下である六方晶窒化ホウ素粉末。【選択図】なし
