| abstract |
The present invention aims to provide a process for producing cellulose nanofibers using a 4-hydroxy TEMPO derivative less expensive than TEMPO and a process capable of rapidly producing homogeneous cellulose nanofibers. Wood cellulose can be efficiently converted into nanofibers by a process for producing cellulose nanofibers comprising treating a cellulosic material with an oxidizing agent in water in the presence of a cellulose oxidation catalyst comprising an N-oxyl compound represented by formula 1 below: n n n n n n n n n n wherein R 1 and R 2 are each independently hydrogen or a C 1 -C 6 straight or branched alkyl group; andn (i) one of R 4 or R 5 is —OR, —OCOR or —OSO 2 R wherein R is a straight or branched carbon chain having 4 or less carbon atoms, and the other of R 4 or R 5 is hydrogen, and R 3 and R 6 are methyl, or (ii) R 4 is hydrogen, and R 5 , R 3 and R 6 are taken together with a piperidine ring to form an aza-adamantane compound having formula 2 below: nn n n n n n n n n n or a mixture thereof, and a compound selected from the group consisting of bromides, iodides and mixtures thereof to prepare oxidized cellulose, and microfibrillating the oxidized cellulose to convert it into nanofibers. |