Sizing Mechanism of Emulsion Rosin-Aluminium lon Systems

本研究的目的是阐明造纸过程中内部施胶处理的两个机理：阴离子乳液-松香施胶/硫酸铝体系湿部助留机理及其施胶机理，得出以下结论：首先，利用裂解气相色谱等分析仪器建立了测定纸张中微量施胶和铝组分的方法。用上述纸片方法研究发现，铝离子加入纸屑后，立即与纸浆纤维中的游离羧基形成离子键。因此，在纸浆表面形成的阳离子位置可以通过离子相互作用吸附阴离子松香乳液。当加入碱性溶液提高纸浆的pH值时，由于松香乳液的分解和其他原因，离子键-纸浆-COO-AI-松香乳液被裂解。因此，乳液松香施胶/铝离子体系在湿部施胶的机理是纸浆纤维中羧基离子键的即时形成。其次，研究了浆料中残留的浆料组分的性质和化学结构，以阐明该体系的施胶机理。使用了以下分析技术：1)纤维素酶处理的纸页残留物的分析，2)有机溶剂提取的纸页的分析，以及3)以13C标记的脂肪酸作为松香施胶剂模型化合物制备的纸页的固体13C-核磁共振分析。结果表明，松香分子以游离酸形式存在于片状结构中，不形成铝盐。此外，保留在纸页中的铝离子被用来控制疏水松香施胶组分在纸浆纤维表面的分布模式或映射结构。

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.