纸张显白液体颜料的系统评估

Evaluation on the Performance of Liquid Whitening Pigment for Paper

显白液体颜料在纸张中的应用越来越广泛,其具有切换迅速、调节方便的特点,可大大降低损纸量,提高造纸企业综合效益,顺应纸机大型化、高速化和连续化的发展趋势。本文结合造纸企业的应用,叙述了开发和使用显白液体颜料时,液体颜料的pH为4.5～5.5、平均粒径为0.2μm、耐光性为7～8级、耐热性为200℃以上、耐酸碱性为4～5级、液体颜料的批次间的色差小于0.5(ΔE≤0.5)及体系为阳离子型最好;同时叙述了颜料结构、体系中高价金属离子的影响;提出了液体颜料贮存稳定性和起泡性的测试方法,对研究开发和选择纸张显白液体颜料的企业有一定的指导意义,并为制定相应技术规范提供了参考依据。

Liquid whitening pigments are being used in the papermaking more and more widely.Their features are capable of being switched quickly and adjusted easily,which are greatly beneficial in reducing the broke of paper,improving the overall efficiency for paper mills,therefore they comply with the development of large-scale,high-speed,and integrated paper machines.Based on the application results from paper mills,this paper suggests that the best liquid pigment should be cationic,and its pH value within 4.5～5.5,average particle size around 0.2 μm,light fastness 7～8 grade,heat resistance more than 200 ℃,acid and alkali resistance 4～5 grade,color differences between different batches of liquid pigment（ΔE） less than 0.5,in addition,the chemical structures of the pigments and the influence of high valent metal ions in the system on the performances of the pigments should be investigated.The paper also proposes the methods of testing the storage stability and foaming properties of the liquid pigments.The information given in this paper can be of good guidance in developing highly efficient liquid whitening pigments,and also as a reference for formulating the corresponding technical specifications.