| 摘要 |
Selected chlorohydrin and cationic compounds containing nitroxide or hydroxylamine moieties are effective in stabilizing pulp or paper, especially pulp or paper containing lignin, against yellowing and discoloration due to the adverse effects of light. 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. |
