CELLULOSE NANOFIBER, SHEET-LIKE MATERIAL OBTAINED THEREFROM, AND METHOD FOR PRODUCING CELLULOSE NANOFIBER AND SHEET-LIKE MATERIAL

摘要

The present invention provides: a cellulose nanofiber enabling the provision of a high-performance sheet-like material; a method for producing the cellulose nanofiber; and a sheet-like material obtained from the cellulose nanofiber. A bamboo-derived cellulose nanofiber having a cellulose purity of at least 90%, a fiber diameter of 10-20 nm, and a crystallinity of at least 70% can be obtained by a method comprising: (1) a step for subjecting a bamboo material to an alkali treatment and a mechanical treatment to prepare bamboo fibers; (2) a step for delignificating the obtained bamboo fibers; (3) a step for mechanically spreading the delignificated bamboo fibers; (4) a step for removing hemicellulose from the spread bamboo fibers; and (5) a step for removing metal components from the bamboo fibers from which hemicellulose has been removed. A high strength sheet material having a tensile strength of 7-200 N for a basis weight of 10-210 g/m2 or a high strength sheet material having a tensile strength of 7-200 N for a density of 0.3-1.1 g/cm3 can be obtained by making this cellulose nanofiber into a sheet.