| 摘要 |
PROBLEM TO BE SOLVED: To provide bleached pulp in which unbleached pulp obtained by performing digestion of a lignocellulosic material is performed by alkali oxygen delignification, then performed by persulfuric acid treatment in which mirabilite or sesquicarbonate mirabilite inclusion solution is added in an acidic region, and then performed by an (ECF,TCF) multistage bleach process in which chlorine and hypochlorite are not used to produce the bleached pulp, and lowering of a pulp viscosity is little.SOLUTION: An unbleached pulp obtained by performing digestion of a lignocellulosic material is performed by alkali oxygen delignification, pulp after the alkali oxygen delignification is performed by hydrogen peroxide treatment by an initial reaction at pH of 1.5-4.5 and at a reaction temperature of 50-85°C, and is performed by persulfuric acid treatment under the existence of mirabilite and/or sesquicarbonate mirabilite, and an amount of hexeneuronic acid in the bleach pulp is made at most 15 mmol per 1 kg of bone dry pulp. |
