| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for deinking waste paper, capable of providing a deinked pulp remaining only small amount of residual ink by efficiently micronizing an ink having difficulty in release by a conventional deinking method, such as toner, offset ink for a magazines made of woody paper, etc., removing the ink from fibers and dispersing the ink in process water, in a flotation process or a washing process. SOLUTION: This method for deinking waste paper is characterized in that in deinking waste paper, an ink releasing process with mechanical power for main component ink contained in the waste paper is carried out by using one or more kinds of surfactants having a surface tension of +2 to -5 mN/m range, preferably 0 to -3 mN/m range against a value of a surface tension corresponding to a dispersion component of a surface free energy of a main component ink.</p> |
