The Effect of Filler Contents and Particle Sizes on the Porous Structure and the Mechanical Strength of Highly Filler-Containing Papers (Filler Silica: SD-8 and PW-20)

抄録

Highly filler-containing paper was prepared with two kinds of silica of different size, and the effects of filler sizes and contents on the sheet properties, such as pore volume, pore size distribution and physical strength were investigated. The sheet prepared without Filler (filler-free sheet) mainly has pores of 2-5μm diameter by a mercury intrusion porosimeter measurement. Sheets containing silica kept the pore structure of the filler-free sheet indifferent to the filler type and its content up to 50% or more. Silica of 26.1μm diameter (PW-20) couldn't increased the pore volumes of sheets containing it more than 30% over that of the filler-free sheet, even at its content of 75%. On the contrary, sheets containing silica of 9μm diameter (SD-8) marked an increase of pore volume up to four times over that of the filler-free sheet at the silica content of 85%. The mechanical strenght of the loaded paper fell down remarkably with filler contents, especialy in the case of the SD-8 sheets. These behavior of the pore volume increase and the paper strength reduction was explained by the difference of filler particle sizes.