Mechanism of size retention on handsheets prepared in rosin soap size-alum systems

The mechanism of rosin size retention in rosin soap size-alum systems was studied on the basis of sizing behavior and the rosin size and aluminum contents of handsheets prepared under normal and particular conditions. Rosin size, aluminum, and calcium contents of handsheets prepared with various stirring times of pulp suspensions after pH adjustment suggested that rosin size components adsorbed on pulp fibers predominantly have the structure of free rosin acid rather than rosin aluminum or calcium salt. When a carboxyl group-blocked pulp was used, the rosin size content clearly decreased. This result shows that pulp carboxyl groups play a significant role in rosin size retention. Electrostatic interactions between dissociated carboxyl groups of pulps and anionic rosin size components through cationic aluminum compounds must be present in pulp suspensions. On the other hand, nonionic interactions in pulp suspensions, which occur particularly around pH 6.2–6.5, may also contribute to rosin size retention and appearance of sizing features. When the carboxyl group blocked pulp was used, some rosin size components were retained in the handsheets in largely coagulated form, resulting in no or quite low sizing levels, when the handsheets were dried at 20°C.This research was presented in part at the 64th pulp and paper research conference of Japan TAPPI, Tokyo, June 1997     

Retention behavior of size and aluminum components on handsheets in rosin-ester size/alum systems

Anionic emulsion sizes consisting of rosin triglyceride esters and partly fortified rosin acids (i.e., rosin-ester sizes), have recently been used as internal sizes for alkaline papermaking. In this study, handsheets were prepared from pulp suspensions with alum and a rosin-ester size under various conditions, and sizing degree and size and aluminum contents of the handsheets were determined. Aluminum compounds originating from alum added to the pulp suspensions behave as retention aids of the rosin-ester size even in alkaline papermaking under limited conditions. Carboxyl groups in pulp are the primary retention sites of aluminum compounds in pulp suspensions. They form cationic sites on pulp fibers, and thus the anionic size emulsion particles are adsorbed on pulp fibers by electrostatic interactions. However, the cationic charges of aluminum compounds on pulp fibers decrease and finally disappear completely with the lapse of time after the alum addition by forming ionic bonds between the cationic sites and OH^– ions. Thus, pH values of the pulp suspensions and timing of the size addition strongly influence the retention values of the rosin-ester size and the resultant sizing features.This research was presented in part at the 1995 autumn meetings of the Society of Fiber Science and Technology Japan in Hamamatsu, October 1995     

Solid-state13C-NMR analysis of size components in handsheets prepared by fatty acid soap size-alum systems

The mechanism of paper sizing in fatty acid soap size-alum systems was studied by structural analyses of the size components in handsheets prepared with¹³C-labeled fatty acid soap size. Patterns of sizing performance and aluminum content of the handsheets were similar to those for the rosin soap size-alum sizing systems, although the patterns of calcium content were different. Solid-state¹³C-nuclear magnetic resonance analysis of the handsheets revealed that fatty acid calcium salt was the predominant size component in the handsheets prepared using tap water. This calcium salt is formed from the fatty acid soap size (fatty acid potassium salt) by ion exchange with calcium ion in pulp suspensions and retained on pulp fibers through aluminum compounds originating from alum added. On the other hand, when deionized water was used, free fatty acid was the major component in the handsheets. Fatty acid aluminum salt was present as a minor component in the handsheets prepared in both tap water and deionized water systems. Therefore, all size components (i.e., fatty acid calcium salt, free fatty acid, fatty acid aluminum salt) seem to contribute to the appearance of sizing features.This research was presented in part at the 64th Pulp and Paper Research Conference of Japan TAPPI, Tokyo, June 1997     

Factors influencing retention behavior of aluminum compounds on handsheets

Handsheets were prepared with aluminum sulfate under various conditions of pulp suspension, and factors influencing retention behavior of aluminum components on the handsheets were studied on the basis of their aluminum contents. When deionized water was used in the handsheet-making process, aluminum contents in the handsheets had a plateau level of 0.7mg/g in the range of 1%–8% Al₂(SO₄)₃ addition levels on dry weight of pulp. On the other hand, when tap water was used aluminum contents increased up to 5.6 mg/g, increasing the Al₂(SO₄)₃ addition levels to 8%. The high aluminum contents in the handsheets are explained in terms of pH and the presence of calcium ions from the tap water used. Cationic aluminum species, which are formed from aluminum sulfate added to pulp suspensions, are primarily adsorbed on pulp fibers by electrostatic interactions with carboxyl groups in the pulp, competing with OH^– ions in water. These aluminum components, once adsorbed on pulp fibers by ionic interactions, are not removed from the fibers by extending the stirring time of the pulp suspensions.This research was presented in part at the 48th annual meeting of the Japan Wood Research Society in Shizuoka, April 1998     

Adsorption behavior of aluminum compounds on pulp fibers at wet-end

Various aluminum compounds were added to pulp suspensions, and the adsorption behavior of their aluminum components on pulp fibers was studied. Aluminum contents in the handsheets were determined using an energy dispersive X-ray analyzer attached to a scanning electron microscope and an X-ray fluorescence analyzer. Although aluminum contents in the handsheets increased with increasing additions of the aluminum compounds, the detailed adsorption patterns varied among the aluminum compounds used. Their chemical structures and the pH values of the pulp suspensions greatly influence the adsorption behavior. When fines are present in the pulp suspensions, the aluminum components are predominantly adsorbed on the fines, probably due to their larger surface areas or the higher carboxyl contents compared to those of coarse fibers. Not only aluminum flocs but also far smaller components such as various aluminum cations seemed to be adsorbed on pulp fibers. Most aluminum flocs, which are formed in pulp suspensions by reacting with OH and entrapped in a fiber matrix by filtration effects, are removable by repeated mechanical agitation of the pulp suspensions.     

Intrafiber distribution of aluminum components in alum-treated handsheets

The distribution of aluminum components in cross sections of pulp fibers for alum-treated handsheets was successfully measured by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis. In this case, gas-phase osmium coating of paper samples is necessary for the samples to have improved stability to long-term irradiation by electron beams at high magnification during the SEM-EDX measurements. The EDX line-analysis method was superior to the elemental mapping image method in the quantification of aluminum components. According to the SEM-EDX measurement for handsheets prepared from a pulp suspension by adding 2% (on dry weight of pulp) aluminum sulfate, the aluminum components were distributed almost homogeneously in the cross sections of pulp fibers. Aluminum species with smaller sizes than those of A1(OH)₃ flocs could probably penetrate the pulp fibers. Thus, aluminum components present only at the pulp fiber surfaces may contribute to retention of colloidal substances in pulp suspensions. From this aspect, a large amount of aluminum components present in the inside pulp fibers may be wasted.This report was presented at the 49th annual meeting of the Japan Wood Research Society at Tokyo, April 1997     

Fiber charge characteristics of pulp suspension containing aluminum sulfate

Fiber charge characteristics of pulp suspensions containing aluminum sulfate were investigated with relation to adsorption behavior of aluminum components on the pulp fibers by streaming potential measurement using a particle charge detector, X-ray photoelectron spectroscopy, and X-ray fluorescence analysis. When aluminum sulfate was added to a pulp suspension prepared using deionized water, a streaming potential of the suspension went from negative to slightly negative according to the adsorption of aluminum components on the pulp fibers. Subsequent addition of a dilute NaOH solution to the suspension drastically cationized the fibers in the pH range of around 5 by predominant and homogeneous adsorption of cationic aluminum complexes on the fiber surfaces. However, the aluminum flocs that formed heterogeneously on the fiber surfaces at higher pH by further alkali addition made nearly no contribution to cationization of the fibers, although the abundant aluminum components were retained in the pulp sheets. Therefore, only aluminum cations adsorbed uniformly on the fiber surfaces perform well to control the charge properties of the pulp fibers at the wet end; and the preferential aluminum adsorption behavior on the fiber surfaces, by utilizing the required amounts of hydroxyl ions, probably accounts for the effective cationization of the fibers under acidic to neutral papermaking conditions.This research was presented in part at the presymposium of the International Symposium on Wood and Pulping Chemistry, Seoul, June 1999; at the International Symposium on Environmentally Friendly and Emerging Technologies for a Sustainable Pulp and Paper Industry, Taipei, April 2000; and at the 2000 annual meeting of the Society of Fiber Science and Technology, Japan, Kyoto, June 2000     

Studies on interactions between aluminum compounds and cellulosic fibers in water by means of27Al-NMR

Interactions between pulp fibers and aluminum compounds in pulp suspensions were studied using fibrous cellulose (FC) and fibrous carboxymethylcellulose (FCMC) powders as models of pulp fibers by X-ray fluorescence analysis and²⁷Al nuclear magnetic resonance. When deionized water was used at pH 4–5, water-soluble cationic aluminum species (Al³⁺, aluminum oligomer, and polyaluminum species) were adsorbed on the solid FCMC, forming carboxylic acid aluminum salts by cation exchange. The formation of these nondissociated pulp-COOAl type structures in paper sheets may contribute to some decreases in hydrophilic property. On the other hand, the water-soluble cationic aluminum species had nearly no interactions with hydroxyl groups of solid cellulose in the suspensions at pH 4–5. When tap water was used at pH 5–7, some aluminum components were retained on not only FCMC but also the FC sample. Probably, water-insoluble Al(OH)₃ flocs are formed in the suspensions at pH 5–7 and retained on the FC sample by simple filtration effect. Therefore, two mechanisms of the aluminum retention (i.e., electrostatic interactions and a simple filtration effect) may exist between pulp fibers and aluminum components in the practical papermaking process.This research was presented in part at the 5th annual meeting of the Japan Cellulose Society, Kyoto, July 1998     

阳离子纸浆纤维的制备及其用作造纸湿部添加剂的研究(英文)

Cationized pulp fibers （CPF） were prepared by the adsorption of a novel biodegradable cationic ester quaternary ammonium salt （31441） on bleached softwood kraft pulp fibers. The optimized conditions for the CPF preparation were： 4% of 31441 （based on oven-dry pulp）, 80℃ and 30 rain. The CPF was characterized by FT-IR, SEM and XPS. Experimental results showed that the CPF improved the retention of precipitated calcium carbonate （PCC） filler significantly. With 0.9% CPF （based on oven-dry pulp）, the retention of PCC increased from 57.53% to 72.21%. The physical properties of paper were also slightly improved. The tensile strength and burst strength of the paper with CPF were higher than those with CPAM. CPF addition had no effect on the stock drainage.     

Application of cationic polymer prepared from sulfuric acid lignin as a retention aid for usual rosin sizes to neutral papermaking

Cationic polymers that acted as the retention aids for usual rosin sizes in neutral papermaking were prepared from sulfuric acid lignin (SAL), one type of acid lignin. To convert SAL to the cationic polymer (MP-SAL), SAL was phenolated and then treated by the Mannich reaction to introduce the amino groups. In the MP-SAL single system, MP-SAL exhibited high sizing effectiveness in neutral papermaking with the rosin emulsion size. However, MP-SAL showed no sizing effectiveness when soap rosin size was used. MP-SAL showed increased sizing effectiveness as the pK _a of the introduced amino group increased. From this and comparison of the sizing degrees of MP-SAL and polyethylenimine, which possesses a linear structure, it was suggested that the sizing effectiveness was not only affected by the charge density and molecular weight, but also by the basicity of the introduced amino groups and the molecular structure of the retention aid. In the alum–MP-SAL dual system, alum and MP-SAL synergistically enhanced the sizing effectiveness in the rosin emulsion sizing at neutral pH. In turn, this allowed a decrease in the MP-SAL dosage and resulted in a small decrease in brightness.Part of this report was presented at the 48th Lignin Symposium, October 2003, Fukui     

中性松香施胶剂的制备及施胶特性

本研究制备了多种烃基松香酯－松香施胶剂及松香甘油酯－松香施胶剂,并对其在中、碱性造纸施胶中的应用进行了探讨。施胶结果表明,松香甘油酯－松香施胶剂能有效地用于中、碱性施胶,然而其它烃基松香酯－松香施胶剂在同样条件下却无施胶效果。这意味着中性松香胶施胶剂的制备及性能并非完全取决于松香羧基的改性而是松香酯的结构有关。虽然碱性填料碳酸钙的添加引起一定程度的施胶效果的下降,松香甘油酯－松香中性施胶剂在含有碳     

阳离子聚丙烯酰胺乳液对木浆增强作用的研究

以丙烯酰胺和二甲基二烯丙基氯化铵(DDAC)为主单体通过自由基共聚反应合成了水包水型阳离子聚丙烯酰胺(CPAA)乳液增强剂,并探讨了在漂白木浆中的应用条件如CPAA乳液用量、反应时间、硫酸铝用量、浆料pH值、搅拌速度对其增强效果的影响。结果表明,当CPAA乳液用量为0.8%(对绝干浆)、pH值7.0、反应时间10 m in、硫酸铝用量为0.5%(对绝干浆)、搅拌速度150 r/m in时,纸页裂断长和撕裂指数与未加助剂时相比依次增加28.7%和12.4%。红外光谱分析表明,合成的CPAA乳液具有预期设计结构。分析添加乳液前后纸页的环境扫描电镜照片对CPAA乳液的增强机理作了初步探讨。     

Modification of softwood kraft pulp with carboxymethyl cellulose and cationic surfactants

An elemental chlorine-free (ECF)-bleached soft-wood kraft pulp was treated first with a carboxymethyl cellulose (CMC, degree of substitution 0.3, 1% on pulp) and then with alkyltrimethylammonium bromides (alkyl chain lengths of C₁₀ to C₁₆). Surprisingly, the treatment with dodecyltrimethylammonium bromide (C₁₂TAB) markedly increased the internal and tensile strengths of the handsheets prepared from the modified pulp. Environmental scanning electron microscopy (ESEM) showed that these properties could be partly explained by the “rope/gum-like” bridges that were formed between the fibers.     

Wet-end properties of cationic graft terpolymerized polyacrylamides

To improve the wet-end properties of linear-type copolymerized polyacrylamide (co-PAM), three types of cationic co-PAM were prepared by graft copolymerization, and their effects on the drainage, paper strength, and filler retention were investigated. Of the three synthesized terpolymers, dextrin-acrylamide-2-(dimethylamino)-ethylmethacrylate graft terpolymers (Dex-graft-(AM-DMAEMA)) moderately improved the wet-end properties compared with the other two graft terpolymers prepared. Notably, addition of 0.1% (on dry pulp) Dex-graft-(AM-DMAEMA) showed high filler retention of 78%. All of the prepared graft terpolymers showed equal or improved wet-end properties compared with acrylamide-2-(dimethylamino)ethylmethacrylate copolymer (AM-DMAEMA), which is a standard cationic co-PAM of similar moleculer weight.Part of this paper was presented at the meeting of the Chubu Branch, Japan Wood Research Society, Kakamigahara, September 13–14, 2000     

阳离子型松香施胶剂的制备

以非离子型聚合物改性得到阳离子化剂,通过转型法成功制得了阳离子型分散松香施胶剂(CDRS),并对其性质进行了表征。CDRS为白色均一乳液,其Zeta电位为 26mV,体积平均粒径为0.271μm,一致性为0.404,粒径分布较好。在pH值6.0、Al2(SO4)3用量1%的条件下,CDRS对再生纸浆的施胶度为40s,施胶效果接近对照样品,耐老化性能则优于对照样品Hi-phase35。浊度实验和扫描电子显微镜观察表明,由于游离松香的皂化作用,CDRS的施胶效果随着pH值的升高而迅速下降。由于成本低,制备方法简单,在近中性条件下施胶效果较好。     

丙烯酰胺聚合物对阳离子分散松香施胶剂性能的影响

就丙烯酰胺聚合物的组成,分子量对阳离子分散松香胶性能的影响作了初步探讨,并对丙烯酰胺系聚合物制备工艺作了全面分析研究,得出了符合阳离子松香胶制备要求的聚合物生产工艺条件。     

浅色歧化松香钾皂的制备

实验以固体歧化松香和氢氧化钾溶液进行皂化反应制备浅色25%歧化松香钾皂,研究反应温度,皂化时间,酸值,脱色剂对反应的影响。结果表明在反应温度80℃,皂化时间75 min,酸值（KOH）2.0 mg/g,脱色剂加入量为反应物质量的0.2%的条件下,可制备出固含量为25%的浅色歧化松香钾皂,加纳色号较与现行方法制备的产品低2个色级。     

阳离子松香施胶剂的研究综述

阳离子松香施胶剂的研究对我国造纸和松香行业具有十分重要的意义。文中通过概述施胶剂的发展,对比说明了阳离子松香施胶剂的优点,还简单介绍了美国和加拿大的几个专利,并综述了目前国内的研究状况。     

负载型纳米非晶合金NiB/MCM-41催化松香加氢反应性能研究

将采用化学还原沉积法制备的负载型非晶合金NiB/MCM-41中孔分子筛催化剂用于松香的氢化反应,表现出很高的加氢催化活性。研究确定在Ni负载量为13%～15%、反应温度180～190℃、反应压力7～9MPa条件下加氢反应5h,去氢枞酸(DEHAA)、枞酸(AA)在加氢产物中的含量分别小于2.5%和0.5%,且在催化剂重复使用过程中加氢产物分布基本保持稳定。分别采用XRD、TEM、EDAX、ICP和比表面测定等手段对催化剂进行了表征。研究表明:NiB活性组分具有非晶结构特征、催化剂具有典型的中孔结构和较大的比表面积。     

松香分析中影响不皂化物含量的关键因素及机理研究

研究了在脂松香分析测定过程中影响松香不皂化物含量测定的关键因素及其影响机理,讨论了树脂酸在皂化过程中的形态变化特征及其导致不皂化物需要进行树脂酸校正操作和计算的理论依据。结果表明,马尾松松香的不皂化物中易挥发组分最多,湿地松松香的不皂化物含量较高,易挥发组分含量也相对较高,加勒比松松香和南亚松松香不皂化物中可挥发性物质较少。随着烘干温度的提高,松香中不皂化物的含量降低,但高温可能明显地使松香不皂化物中易氧化的醛类物质等发生了部分氧化,致使4种松香不皂化物的酸价则呈增加的趋势,但是,松香不皂化物中存在的酸性应主要来源于由强碱和弱酸形成的松香树脂酸盐类与松香树脂酸之间的电离平衡反应。