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). ##STR00001##

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). ##STR00001##

Method for sulphation and phosphorylation of a cellulose substrate for imparting anti-flame properties to the substrate in which at least one phosphonic acid of formula (I):
PO(OH).sub.2—R—PO(OH).sub.2,   (I)
is used as a catalyst of sulphation and a phosphorylating agent and relative substrate.

Method for sulphation and phosphorylation of a cellulose substrate for imparting anti-flame properties to the substrate in which at least one phosphonic acid of formula (I):
PO(OH).sub.2—R—PO(OH).sub.2,   (I)
is used as a catalyst of sulphation and a phosphorylating agent and relative substrate.

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).

##STR00001##

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).

##STR00001##