Abstract: Provided is a method for producing a chemically modified cellulose fiber with which fibrillation can be performed along with sulfation reaction. The method for producing a chemically modified cellulose fiber includes a step (a) of treating a cellulose fiber with sulfamic acid to allow a cellulose fine fiber which is a constituent of the cellulose fiber to react with the sulfamic acid, thereby substituting some of hydroxyl groups of cellulose with a substituent represented by a structural formula (1) below (where M represents a monovalent to trivalent cation), and a step (b) of performing fibrillation simultaneously with the step (a).

Abstract: A sulfated cellulose fiber having a cellulose I crystal structure is provided. A chemically modified cellulose fiber which has a cellulose I crystal and in which some hydroxyl groups of cellulose are substituted with a substituent represented by formula (1). An amount of the substituent introduced is 0.1 mmol to 3.0 mmol per 1 g of the chemically modified cellulose fiber, and an average degree of polymerization is 350 or more. (In formula (1), M represents a monovalent to trivalent cation.) In the production of the chemically modified cellulose fiber, a cellulose fiber is treated with sulfamic acid while maintaining a cellulose fiber shape to allow sulfamic acid and a cellulose fine fiber which is a constituent of the cellulose fiber to react with each other.

Abstract: Provided is a method for producing a chemically modified cellulose fiber with which fibrillation can be performed along with sulfation reaction. The method for producing a chemically modified cellulose fiber includes a step (a) of treating a cellulose fiber with sulfamic acid to allow a cellulose fine fiber which is a constituent of the cellulose fiber to react with the sulfamic acid, thereby substituting some of hydroxyl groups of cellulose with a substituent represented by a structural formula (1) below (where M represents a monovalent to trivalent cation), and a step (b) of performing fibrillation simultaneously with the step (a).

Abstract: A sulfated cellulose fiber having a cellulose I crystal structure is provided. A chemically modified cellulose fiber which has a cellulose I crystal and in which some hydroxyl groups of cellulose are substituted with a substituent represented by formula (1). An amount of the substituent introduced is 0.1 mmol to 3.0 mmol per 1 g of the chemically modified cellulose fiber, and an average degree of polymerization is 350 or more. (In formula (1), M represents a monovalent to trivalent cation.) In the production of the chemically modified cellulose fiber, a cellulose fiber is treated with sulfamic acid while maintaining a cellulose fiber shape to allow sulfamic acid and a cellulose fine fiber which is a constituent of the cellulose fiber to react with each other.