| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1994: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1993: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Research Abstract |
The goal of this research was to clarify two mechanisms of internal sizing treatments in paper-making process ; retention mechanism of the anionic emulsion-rosin size/aluminium sulfate system in wet-end and its sizing mechanism of size components retained in sheet, and the following results were obtained.
First, the methods for determining small amounts of size and aluminium components in sheets were established uisng pyrolysis-gas chromatography and other analytical apparatus. it was found using the above methods of paper-sheets that aluminium ions added to paper stodck immediately formed ionic linkages with dissociated carboxyl groups in pulp fibers. Thus, the cationic sites of pulp surfaces formed at the Pulp-COOAI can adsorb anionic rosin emulsions by inonic interactions. When pH of the paper stock increased by the addition of an alkaline solution, the ionic linkages, Pulp-COO-AI-Rosin emulsion, were cleaved by decomposition of rosin emulsions and other reasons. Therefore, the retention mechanism of emulsion rosin size/aluminium ion system in wet-end is governed by the immediate formation of ionic linkages at the carboxyl groups in pulp fibers.
Next, the properties and chemical structures of size components retained in sheets were studied to elucidate the sizing mechanism of this system. The following analytical techniques were used ; 1) analyzes of cellulase-treated residues of paper-sheets, 2) extractions of paper-sheets with organic solvents, and 3) solid-state 13C-NMR analyzes of paper-sheets prepared with 13C-labled fatty acids used as model compounds of rosin size. The results showed that rosin molecules exsited in sheet as free acid without forming aluminium salts. Furthermore, aluminium ions retained in sheets essmed to govern the distribution patterns or mapping structures of hydrophobic rosin size components on pulp fiber surfaces.
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