Selected polymeric stabilizers with pendant nitroxide, hydroxylamine or hydroxy-ammonium salt groups B are water soluble or water dispersible and have high affinity to pulp or paper. These stabilizers prevent the loss of brightness and enhance resistance to yellowing in pulp or paper, especially pulp or paper containing lignin. These compounds are added at various points in the paper-making process, especially at the wet ends, making the need for water soluble or water dispersible materials having high affinity for pulp or paper essential. This performance is often further enhanced by the presence of one or more coadditives selected from the group consisting of the UV absorbers, the polymeric inhibitors, the nitrones, the fluorescent whitening agents and metal chelating agents. Combinations of hydroxylamines or their salts, benzotriazole or benzophenone UV absorbers and a metal chelating agent are particularly effective.
具有偏
氮氧自由基、
羟胺或羟基
铵盐基团的聚合物稳定剂B是
水溶性或
水分散性的,并且具有高亲和力,可以防止漂白度的损失和增强含有
木质素的纸浆或纸张的抗黄化性能。这些化合物可以在造纸过程的不同阶段添加,特别是在湿端,因此需要具有高亲和力的
水溶性或
水分散性材料是必不可少的。这种性能通常通过与
紫外线吸收剂、聚合
抑制剂、亚
硝基化合物、
荧光增白剂和
金属
螯合剂等共同添加剂之一或多个的存在而进一步增强。
羟胺或其盐、苯并三唑或苯并
酚紫外线吸收剂和
金属
螯合剂的组合特别有效。