| 摘要 |
PURPOSE:To obtain the title filler generating no background fog and excellent in refuse adhesion preventing properties by using amorphous silica wherein a primary particle size due to a scanning electromicroscopic method, a specific surface area of BET method, a silica elementary particle size calculated from said specific surface area and an agglomeration degree defined by a specific formula are specific values. CONSTITUTION:A filler for thermal recording paper is constituted of amorphous silica wherein a primary particle size D1 due to a scanning electromicroscopic method is 100-270nm, apparent specific gravity is 0.24-0.55g/cm<3>, a BET method specific surface area is 200-500m<2>/g, oil absorbancy is 50-120ml/100g and an agglomeration degree defined by formula [average primary particle size D1]/[silica elementary particle size D0] is 10-50. By this constitution, the density of an image can be enhanced while background fog is suppressed and an aqueous dispersion markedly low in viscosity can be prepared and paint excellent in high concn. coating and imparting excellent abrasion resistance to a device at the time of coating can be obtained. |
