Patent ID: 8377563

Claim:
A cellulose nanofiber obtained by a method comprising the steps of: oxidizing a cellulosic material with an oxidizing agent in the presence of: (1) N-oxyl compound(s), and (2) compound(s) selected from the group consisting of bromide, iodide and mixtures thereof to prepare an oxidized cellulose; and finely grinding the oxidized cellulose in a wet condition to convert the oxidized cellulose into nanofibers having an amount of carboxyl groups of 1.2 mmol or more, based on 1 g absolute dry weight of the cellulose nanofibers, and whose B-type viscosity (60 rpm, 20° C.) as an aqueous solution at a concentration of 2% (w/v) is from 500 to 7000 mPa·s.