中性施胶剂AKD在造纸工业中的应用

简述了AKD施胶剂的合成、施胶机理与特点及影响因素。作为一种有效的合成中性施胶剂,AKD将有广阔的市场。     

无碳复写原纸AKD中性施胶助留体系的优化

介绍无碳复写原纸生产中使用AKD中性施胶剂存在的一些问题,通过合理调整助留体系解决生产中的不足,达到预期的质量目标。     

Heterogeneous Reactions between Starch and AKD under Solvent-free Conditions

Oxidized starch powder and cationic starch solution were reacted with alkyl ketene dimer(AKD) under heterogeneous conditions at 70℃ for 12 h.The AKD molecules reacted with starch hydroxyl groups to form β-keto ester linkages under the above conditions.The reaction products were separated into CHCl_3-soluble and CHCl_3-insoluble fractions.FT-IR spectroscopy,SEM,Xray diffraction,and TG-DTA analyses of the CHCl_3-insoluble fraction indicated that β-keto ester substituents were introduced to hydroxyl groups on the starch surfaces.The results indicated that hydrogen bonds between the starch molecules were disrupted under heterogeneous conditions upon heating.The activity and accessibility of hydroxyl groups were enhanced,as a result of which β-keto ester bonds were produced between AKD and starch.Based on these results,we speculate that the β-keto esters which existed in the sheets sized by AKD emulsions were generated by the reaction between AKD and starch.     

聚乙烯醇改性AKD用于纸张施胶

针对烷基烯酮二聚体（AKD）使用过程中容易水解等不利因素,该研究用聚乙烯醇（PVA）对AKD进行改性,使AKD能够在较高温度下使用而不水解,而且纸张施胶滞后减少,应用在表面施胶完成纸张的施胶功能,取消了浆内施胶,实现了一体化施胶。     

表面施胶型AKD用乳化剂的中试

综述了表面施胶型AKD用乳化剂在中试生产过程中的注意事项,并与实验室工艺条件进行了比较。通过调节中试过程中的生产环节,最终使该新型AKD用乳化剂成功生产,满足了市场更新换代的需要。     

AKD中性施胶在双胶纸中的生产实践

本介绍了AKD中性施胶剂在80g/m^2双胶纸中的实际生产应用情况，其中详细地通过图表和数据阐述AKD的使用方法和成本分析。中性施胶和酸性施胶相比，除了能有效地改善纸张的各项物理性能指标，还能减少对环境的污染和创造可观的经济效益。     

Influence of Fillers on Sizing Efficiency and Hydrolysis of Alkyl Ketene Dimer

The influence of various fillers on sizing efficiency, adsorption and hydrolysis of alkyl ketene dimer (AKD) has been investigated. Results indicated that the precipitated calcium carbonate (PCC) improved AKD retention, both bound and unbound. The sizing efficiency was reduced as PCC contents increased, which might be attributed to the decrease in the relative AKD dosage to fibres and AKD hydrolysis promoted by PCC. Less amount of AKD was adsorbed on PCC, compared with calcined clay and TiO₂ fillers under the same conditions. Hydrolysis studies indicated that PCC had a more detrimental effect on AKD hydrolysis than clay and TiO₂.     

阳离子活性聚合物/AKD乳液的施胶和增强作用

以合成的阳离子活性聚合物作为高分子乳化剂,制备了阳离子活性聚合物/AKD乳液。研究了乳液制备过程的主要影响因素,并比较了阳离子活性聚合物/AKD乳液与传统AKD乳液对纸张的增强性能。结果表明,当m(阳离子活性聚合物)∶m(AKD)=0.30时可制得稳定乳液,乳液具有很好的施胶和增强效果,且明显优于传统的AKD乳液。当乳液(固含量为15%)以用量0.13%(对w=5%的淀粉溶液)进行施胶时,纸张施胶度可以达到40s,环压指数提高了13.6%,耐折度提高了185%。纸张表面的SEM分析显示,经阳离子活性聚合物/AKD乳液施胶后的纸张表面,纤维间的界面变的模糊,纤维结合更加紧密。     

镁铝水滑石用作造纸填料对AKD施胶效果的影响

考察了镁铝水滑石(HT)用作造纸填料对AKD施胶效果的影响,结果表明,工业级HT对AKD的施胶效果有较大影响.随着HT用量的增加,AKD的施胶效果迅速降低,直至加填纸无疏水性能,HT加填纸的吸水性(Cobb值)会随着AKD用量的增大而减小,HT用量为10%、AKD用最为0.4%时,HT加填纸的吸水性降至30 g/m2.此外,还考察了自制的不同镁铝比HT及镁铝比为5:1型不同层间阴离子的HT作为填料对纸张施胶性能的影响.结果表明,自制HT加填纸的吸水性均在14～17 g/m2之间,其中SO2-4-HT对AKD施胶效果的影响与PCC的相似.     

阳离子松香/AKD中性施胶剂的制备及应用

以N甲-基吡咯烷酮（NMP）为助溶剂,丙烯酰胺（AM）、甲基丙烯酰氧乙基三甲基氯化铵（DMC）、丙烯酸十八酯（ODA）、苯乙烯（St）为单体,通过无皂乳液共聚反应合成了阳离子高分子乳化剂,并制备了阳离子松香/AKD乳液。研究了高分子乳化剂合成中AM、DMC用量对乳液稳定性的影响,乳液中松香、AKD、高分子乳化剂质量比对乳液稳定性及施胶性能的影响,以及纸浆pH值、乳液用量对施胶效果的影响。结果表明：AM用量为35%,DMC用量为15%,松香、AKD和高分子乳化剂的质量比为11∶4∶3时乳液稳定性较好。适宜的施胶条件为：采用逆向施胶工艺,松香、AKD和高分子乳化剂的质量比为11∶4∶3,纸浆pH值为6,乳液用量为1%。