Nippon Paper Industries Co., Ltd.

Masahiko Fukazawa

Shoichi Miyawaki

Shiho Tsuji

Takeshi Iimori

Tomoaki Koyanagi

Naoyuki Tamura

Provided is a method which is capable of producing a cellulose nanofiber dispersion liquid that has a low viscosity and excellent fluidity even at a high concentration, while exhibiting excellent transparency. In a method for producing cellulose nanofibers, wherein a cellulosic starting material is oxidized in water using an oxidant in the presence of an N-oxyl compound and a compound that is selected from the group consisting of a bromide, an iodide and a mixture thereof and the thus obtained oxidized cellulose is defibrated and dispersed, pulp which is obtained by carrying out kraft cooking after a hydrolysis process is used as the cellulosic starting material.

Method for producing cellulose nanofibers

Cellulose nanofibers are produced by means of a method comprising a step (A) of oxidizing a cellulosic starting material in the presence of an N-oxyl compound and a step (B) of forming the oxidized cellulosic starting material into nanofibers by defibrating the oxidized cellulosic starting material, and a step (C) of performing at least one selected from the following steps: a step (C-1) of treating the cellulosic starting material in water having a hydroxide ion concentration of 0.75 to 3.75 mol/L prior to performing the step (A); and a step (C-2) of subjecting the oxidized cellulosic starting material obtained from the step (A) to hydrolysis in an alkaline solution having a pH between 8 and 14 after performing the step (A) and prior to performing the step (B).

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Tokyo, Japan

Masahiko Fukazawa