ADDITIVE FOR PAPERMAKING AND PAPER CONTAINING THE SAME

摘要

Paper improved in air impermeability and smoothness is produced using a papermaking additive which comprises cellulose nanofibers whose aqueous dispersion having a concentration of 2% (w/v) has a Brookfield viscosity (60 rpm, 20°C) of 500-7,000 mPa·s, preferably 500-2,000 mPa·s. This additive is produced by a process which includes oxidizing a raw cellulosic material with an oxidizing agent in the presence of (1) an N-oxyl compound and (2) a bromide, an iodide, or a mixture of these to prepare an oxidized cellulose and subjecting the oxidized cellulose to wet pulverization to reduce the cellulose into nanofibers.