Amorpher silicaartiger Füllstoff

摘要

An amorphous silica-type filler which has an average primary particle diameter (D1) of from 100 to 270 nm as observed by a scanning-type electron microscope, an apparent specific gravity (JIS K 6220 method) of from 0.24 to 0.55 g/cm<3>, a BET method specific surface area of from 200 to 500 m<2>/g, a silica elementary particle diameter (DO) as calculated from the BET method specific surface area of from 5 to 15 nm, and an agglomeration degree (DA), as defined by the equation DA = D1/DO, of from 10 to 50.