阴离子聚丙烯酰胺提高装饰原纸二氧化钛留着效果的研究

装饰原纸对湿强度的要求很高,因而大量使用聚酰胺多胺环氧氯丙烷(PAE)类湿强剂。PAE阳电荷密度较高,使得装饰原纸的湿部抄造体系呈高度阳离子性,反而影响昂贵的二氧化钛填料的留着。为达到既提高二氧化钛留着又不给原纸性能带去不利影响的目的,本研究在常规使用PAE的基础上,合理引入阴离子聚丙烯酰胺(APAM),研究比较了三种不同分子量、不同电荷密度的APAM配合PAE的使用效果。结果表明:分子量越小、负电荷密度越低的APAM能更好地使纸张的匀度得到维持;使用优选后的APAM与PAE配合使用,两者的用量分别为0.02%和0.8%(基于绝干助剂对绝干纸料的百分比)时,相比于单独使用0.8%PAE,可使填料留着率、滤水速率、纸张湿抗张强度和干抗张强度分别提高9.6%、23.1%、71.2%和44.2%。

Improving the retention of titanium dioxide in preparing decorative base paper with anionic polyacrylamide

Polyamide-polyamine epichlorhydrin(PAE)was added in high amount to contribute the high wet strength property that is need by decorative base paper during its manufacturing.However,as the cationic charge density of PAE is moderately high,it turns the wet end system to be highly cationic,which instead impairs the retention of expensive titanium dioxide filler.In order to improve the retention of titanium dioxide without any adverse effect on the performance of the paper,this study reasonably introduced the use of anionic polyacrylamide(APAM)to make a good combination of the conventional use of PAE.Three kinds of APAM with different molecular weight and negative charge density were compared.The results showed that the APAM with the lowest molecular weight and charge negativity was more suitable to maintain the formation of the paper.Compared with the use of PAE alone at 0.8%(dry chemical to dry stock),the use of PAE at 0.8%followed by the use of the optimal APAM at 0.02%could increase the filler retention ratio,stock drainage,wetting and dry strengths of paper by 9.6%,23.1%,71.2%and 44.2%respectively.