SILICEOUS POWDER AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To enhance the flexural strength and the heat resistance to soldering of a resin composition with a spherical silica filled therein while keeping the compactly packed properties and the high fluidity of the excellent properties of the spherical silica. SOLUTION: This siliceous powder has >=0.75 average sphericity, and satisfy at least one of conditions having <=0.50 nN adhesive force to a probe measured by using an interatomic force microscope, having <=95 Pa tensile breaking stress of a powder layer measured by a hung-type two-division cell-type sticking power test, and having both absorption bands of Si-OH at about 4415 cm-1 and Si-OR (R is an alkyl group) at about 4350 cm-1 in an IR spectrum.