Modified Cellulose Nanofibers and Their Manufacturing Methods

摘要

PROBLEM TO BE SOLVED: To provide a modified cellulose nanofiber which can be produced easily and efficiently, has a uniform nanosize, a high crystallinity, a small damage to a fiber shape, a large aspect ratio, and a large water absorption. SOLUTION: A reactive defibrating solution containing a catalyst containing a metal compound and a dibasic carboxylic acid anhydride is permeated into cellulose, the cellulose is esterified and chemically defibrated, and modified with a dibasic carboxylic acid anhydride. A modified defibration step of obtaining modified cellulose fine fibers formed of cellulose containing the form of a metal salt, and stirring by adding a dispersion medium to the obtained modified cellulose fine fibers and stirring to obtain modified cellulose nanofibers. The modified cellulose nanofibers are produced through the steps. The metal compound may be an alkali metal compound (particularly, an alkali metal bicarbonate). The reactive defibrating solution may further contain an aprotic solvent having 25 or more donors. In the stirring step, the modified cellulose fine fibers may be liquid-liquid sheared. [Selection diagram] None