PROCESSES FOR PRODUCING CELLULOSE NANOFIBERS, CELLULOSE OXIDATION CATALYSTS AND METHODS FOR OXIDIZING CELLULOSE

摘要

Disclosed is a process for producing a cellulose nanofiber by using a 4-hydroxy TEMPO derivative which is more inexpensive than TEMPO. Also disclosed is a process for producing a cellulose nanofiber homogeneously within a short period. Specifically disclosed is a process for producing a cellulose nanofiber, which is characterized by comprising the steps of: treating a cellulose raw material with an oxidizing agent in water in the presence of an N-oxyl compound represented by formula (1) or a mixture of the compounds and a cellulose oxidation catalyst selected from the group consisting of a bromide, an iodide and a mixture of the bromide and the iodide to produce an oxidized cellulose; and fibrillating the oxidized cellulose into a nanofiber. The process enable the production of a nanofiber from a wood cellulose with high efficiency. (In the formula (1), R1 and R2 independently represent a hydrogen or a linear or branched C1-C6 alkyl group; and (i) one of R4 and R5 represents -OR, -OCOR or -SO2R [wherein R represents a linear or branched carbon chain having 4 or less carbon atoms], and the other of R4 and R5 represents a hydrogen; and R3 and R6 independently represent a methyl group; or (ii) R4 represents a hydrogen; and R5, R3 and R6 together with a piperidine ring form an azaadamantane-type compound represented by formula (2).)