MANUFACTURING METHOD OF SILICON NITRIDE POWDER

• Main Authors: NAWATA TERUHIKO, NAGAMI TOMOHITO, YAMAMOTO KIKUO
• Format: Patent
• Language: English; Japanese
• Published: 06.04.2017
• Subjects: CHEMISTRY; COMPOUNDS THEREOF; INORGANIC CHEMISTRY; METALLURGY; NON-METALLIC ELEMENTS

PROBLEM TO BE SOLVED: To provide a manufacturing method of silicon nitride powder capable of industrially manufacturing silicon nitride powder containing silicon nitride crystal particle having proper wide particle size distribution, a well formed shape and a large particle diameter.SOLUTION: Silicon nitride powder containing α type silicon nitride crystal particles having average aspect ratio of 1.2 to 2.0 and particles having average particle diameter of 10 μm or more and containing particles with 5 μm or less of 5 to 20 mass% is obtained by conducting a reduction nitriding reaction while adjusting a composition of exhaust gas from a reaction vessel so that a molar ratio of carbon monoxide concentration to nitrogen concentration becomes 0.03 to 0.43 and that carbon monoxide concentration becomes 3 mol% to 30 mol%, in manufacturing silicon nitride by reduction nitriding silicon oxide in the reaction vessel.SELECTED DRAWING: Figure 1 【課題】適度に広い粒度分布を有し、且つ、形状が整った、大粒径の窒化ケイ素結晶粒子を含む窒化ケイ素粉末を工業的に製造することが可能な窒化ケイ素粉末の製造方法を提供する。【解決手段】反応容器内でケイ素酸化物を還元窒化して窒化ケイ素を製造するに際し、該反応容器からの排ガスの組成が、窒素濃度に対する一酸化炭素濃度のモル比が０．０３〜０．４３、一酸化炭素濃度が３モル％〜３０モル％となるように調整しながら、還元窒化反応を行うことにより、平均アスペクト比が１．２〜２．０のα型窒化ケイ素結晶粒子を含み、平均粒子径が１０μｍ以上であり、且つ、５μｍ以下の粒子を５〜２０質量％の割合で含有する窒化ケイ素粉末を得る。【選択図】 図１