Two-dimensional XPS Analysis of Rosin Distribution in Paper Sheets Tub-sized with Dispersed Rosin Size

Abstract

Distribution characteristics of rosin components in paper sheets tub-sized with an anionic dispersed rosin size were investigated by X-ray photoelectron spectroscopy (XPS) to elucidate the factors influencing the sizing efficiency and performance. Base handsheets subjected to tub sizing were prepared from a fines-free pulp with either aluminum sulfate or polydiallyldimethylammonium chloride (PDADMAC). Sizing degrees of tub-sized sheets increased with an increase in aluminum content of the sheets, and good sizing response also appeared in tub-sized sheets only by adding much smaller amounts of PDADMAC than those of aluminum sulfate in the base sheet-making. On the other hand. tub-sized sheets without any cationic additives showed nearly no sizing effect. These results indicated that the cationic compounds, being not limited to aluminum ones, in paper sheets were indispensable for the effective sizing appearance of the surface-sized sheets. These tub-sized sheets were applied to two-dimensional XPS analysis for estimating the rosin distribution on the sheets after vapor-phase bromination. It was suggested that the distribution states of rosin components in the sheets showing poor sizing were distorted by rewetting treatment of the sheets, however, the rosin distribution in well-sized sheets almost remained unchanged, and thus preventing the localization of rosin components by water penetration into paper sheets was a predominant factor to improve the sizing efficiency after the size retention. Possibly, the cationic compounds on pulp fibers must play a significant role to uniformly settle the anionic rosin particles to the fiber surfaces.