Sizing Mechanism of Emulsion Rosin-Aluminium lon Systems

本研究的目的是阐明两种机制内施胶处理的造纸过程；阴离子乳液-松香浆料/硫酸铝体系湿端保留机理及其浆料组分在片材中保留的施胶机理，得到了以下结果。首先，建立了利用热解-气相色谱和其他分析仪器测定薄板中少量尺寸和铝组分的方法。用上述方法对纸张进行研究发现，铝离子加入纸浆后，立即与纸浆纤维中的游离羧基形成离子键。因此，浆液表面形成的阳离子位点可以通过离子相互作用吸附阴离子松香乳剂。当原纸的pH值增加时，由于松香乳剂的分解等原因，离子键浆- coo - ai -松香乳剂发生断裂。因此，乳化液松香浆料/铝离子体系在湿端的保留机制是由浆料纤维中羧基上离子键的直接形成决定的。其次，研究了保留在薄板中的浆料组分的性质和化学结构，阐明了该体系的浆料机理。使用了以下分析技术：1)分析纤维素酶处理过的纸张残渣，2)用有机溶剂提取纸张，3)用13c标记的脂肪酸作为松香大小的模型化合物制备的纸张的固态13C-NMR分析。结果表明，松香分子在薄片中以游离酸的形式存在，不形成铝盐。此外，保留在薄片中的铝离子似乎控制了疏水松香尺寸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.