| 摘要 |
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. |
