| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a resin composition, especially a semiconductor sealing material, of excellent fluidity and moldability and reduced burr formation, to provide an ultrafine powder desirable therefor, and to provide a method for producing an ultrafine powder. <P>SOLUTION: Disclosed are an ultrafine powder having a content of SiO<SB>2</SB>and Al<SB>2</SB>O<SB>3</SB>of 99.5 mass% or higher in terms of oxides, an average particle diameter of 0.05-1.0μm, a coefficient of variation in a particle size distribution of 10-100%, and an ultrafine powder having a content of Al<SB>2</SB>O<SB>3</SB>of 10-99 mass% in terms of an oxide, an inorganic powder having an average particle diameter of 5-50μm and containing 0.5-20 mass% of the above ultrafine powder, and a method for producing an ultrafine powder is one comprising heat-treating an Si source substance and an Al source substance by spraying them into a high-temperature flame formed from a combustible gas and a combustion-assisting gas, wherein the Si source substance and the Al source substance are sprayed from separate burners, and the Si source substance is sprayed from a position 1-20 cm below the position from which the Al source is sprayed. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
