| abstract |
(57) [Summary] [Purpose] In the delignification bleaching of chemical pulp for papermaking, the delignification and high whiteness are promoted without deterioration of the pulp. [Constitution] For chemical pulp for papermaking that has been digested, After high-temperature and high-pressure oxygen bleaching treatment, followed by xylanase enzyme treatment combined with acid treatment or chelating agent treatment, delignification and bleaching with peroxide in an alkaline medium or with peroxide and oxygen. |