| 摘要 |
<p>A deinking method comprising the steps of liberating ink from a waste paper as a raw material and removing the liberated ink from a flotation system, wherein a nonionic surfactant, e.g., a reaction product obtained by adding an alkylene oxide to a mixture of an oil and fat and an alcohol, an alkylene oxide adduct of a fatty acid, or an alkylene oxide adduct of a higher alcohol, is used for the liberation of ink, and the flotation step is effected in the presence of a cationic compound, an amine, an acid salt of an amine or an amphoteric compound at a pH of from 4 to 9, provides a high quality deinked pulp having a high whiteness and a little residual ink spots.</p> |
