Development of High Quality Porous Fillers (Parti) －Study of the Effect of Particle Properties of Porous Fillers on Bulkiness and Opacity of Paper－

摘要

Due to their low specific gravity, porous fillers, including precipitating silica, have, in recent years, been increasingly used as additives (fillers) for the purpose of increasing paper bulkiness (reducing weight). The use of porous fillers has advantages such as continued utilization of existing equipment without the occurrence of discoloration problems inherent with mechanical pulps. However, problems such as degraded paper strength still remain to be solved. In view of this, we have conducted a study in an attempt to develop a high quality porous filler with superior bulkiness performance, excellent opacity and minimal degradation in paper strength. This report reveals that a porous filler with minimized degradation in paper strength, high bulkiness performance, and excellent opacity has been obtained by optimizing the primary particle diameter and the secondary coagulation particle diameter.