ACID-TYPE CARBOXYLATED CELLULOSE NANOFIBERS

The present invention intends to provide an acid type carboxylated cellulose nanofiber having a high viscosity in a low shear region, or to provide an acid type carboxylated cellulose nanofiber having a very short fiber length, and the acid type carboxylated cellulose nanofiber has a carboxy group at least in part of a constituent unit constituting a cellulose molecular chain, wherein a viscosity of water dispersion with a content from 0.95 to 1.05% by mass is 400 Pa·s or higher at a shear velocity from 0.003 to 0.01 s-1at 30°C, or an average fiber length is from 50 to 500 nm and a ratio of fibers having a fiber length of 300 nm or shorter is 50% or higher.