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##

It is an object of the present invention to provide fine fibrous cellulose capable of enhancing transparency and suppressing coloring, when the fine fibrous cellulose are processed into a dispersed solution or a sheet. The present invention relates to fine fibrous cellulose, in which the amount of substituents introduced is less than 0.5 mmol/g and the fiber width is 1 to 10 nm. Moreover, the present invention relates to a dispersed solution and a sheet, each of which comprises fine fibrous cellulose. Furthermore, the present invention relates to a method for producing fine fibrous cellulose, comprising: (A) removing at least a part of substituents from fine fibrous cellulose with a fiber width of 1000 nm or less having the substituents, and (B) performing a uniform dispersion treatment on the resulting fine fibrous cellulose after completion of the (A).

The present invention relates to microfibrous cellulose capable of exhibiting an excellent dispersibility stability and an excellent coating suitability when added to paint.

To this end, the present invention provides fibrous cellulose having a fiber width of 1,000 nm or less and containing an ionic substituent. An amount of the ionic substituent in the fibrous cellulose is 0.10 mmol/g or more and 1.50 mmol/g or less. A polymerization degree of the fibrous cellulose is 150 or more and 515 or less. When the fibrous cellulose is dispersed in a dispersion solvent containing water and isopropanol to obtain a dispersion fluid having a 7:3 mass ratio of water and isopropanol and a viscosity of 2,500 mPa.Math.s at 23° C., and the dispersion fluid is stirred under predetermined stirring conditions, a viscosity change rate falls within ±50% as calculated by the following formula:

viscosity change rate (%)=(viscosity after stirring−viscosity before stirring)/viscosity before stirring×100

Phosphoethanolamine cellulose and methods of making and using it are disclosed. In particular, the invention relates to a method of producing a phosphoethanolamine cellulose biosynthetically using a BcsG phosphoethanolamine transferase for cellulose modification. Recombinant constructs encoding BcsG are described, including constructs encoding BcsG by itself or in combination with BcsE and BcsF, which increase the extent of cellulose modification and the amount of modified cellulose produced. Production of phosphoethanolamine cellulose in cell culture and derivatization of phosphoethanolamine cellulose are also described.

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.

The present invention relates to a product formed of a mixture containing a multivalent cation resin and nanocellulose. The present invention is characterized in that a layer containing the nanocellulose is formed on a layer of the multivalent cation resin so that the multivalent cation resin and the nanocellulose are mixed with each other. The product of the present invention provides a laminate having a nanocellulose-containing layer with excellent gas barrier property and an interlayer adhesion, and the present invention provides also a method for producing the same.

A nanocellulose dispersion liquid including nanocellulose and a protic polar solvent having a dielectric constant of not less than 15 and less than 80 at 25° C. The nanocellulose contains a sulfuric acid group and/or a sulfo group derived from a sulfuric acid treatment and an anionic functional group derived from a hydrophilization treatment. Further, the total amount of the sulfuric acid group and/or the sulfo group and the anionic functional group is 0.20 to 4 mmol/g. Also disclosed is a method for producing the nanocellulose dispersion liquid.

A nanocellulose dispersion liquid including nanocellulose and a protic polar solvent having a dielectric constant of not less than 15 and less than 80 at 25° C. The nanocellulose contains a sulfuric acid group and/or a sulfo group derived from a sulfuric acid treatment and an anionic functional group derived from a hydrophilization treatment. Further, the total amount of the sulfuric acid group and/or the sulfo group and the anionic functional group is 0.20 to 4 mmol/g. Also disclosed is a method for producing the nanocellulose dispersion liquid.

A cellulose nanocrystal composite containing a sulfuric acid group and/or a sulfo group and an anionic functional group, and supporting fine metal particles. The total amount of the sulfuric acid group and/or the sulfo group and the anionic functional group is more than 0.17 mmol/g and not more than 4.0 mmol/g. Also disclosed is a method for producing the cellulose nanocrystal composite which includes treating a cellulose material with sulfuric acid to prepare cellulose nanocrystal containing a sulfuric acid group and/or a sulfo group; subjecting the cellulose nanocrystal to a hydrophilization treatment to prepare cellulose nanocrystal containing a sulfuric acid group and/or a sulfo group and an anionic functional group; and allowing the cellulose nanocrystal to support fine metal particles.