It is an object of the present invention to provide an ultrafine cellulose fiber-containing composition having favorable dispersibility even in the presence of a specific organic solvent. The present invention relates to a cellulose fiber-containing composition comprising cellulose fibers having a fiber width of 1000 nm or less, water, and alcohol, wherein the alcohol is at least one type selected from monovalent primary alcohol, monovalent secondary alcohol, and polyhydric alcohol, and the dielectric constant of the cellulose fiber-containing composition at 25° C. is 55 or more and less than 80.

It is an object of the present invention to provide an ultrafine cellulose fiber-containing composition, regarding which an ultrafine cellulose fiber-dispersed organic solvent slurry can exhibit high viscosity and high transparency. The present invention relates to a cellulose fiber-containing composition comprising cellulose fibers with a fiber width of 1000 nm or less having anionic groups, and metal ions, wherein the cellulose fiber-containing composition comprising organic onium ions as counterions of the anionic groups, and when a solid in the cellulose fiber-containing composition is converted to an absolute dry solid, the content of the metal ions in the absolute dry solid is 80 ppm or more and 700 ppm or less.

It is an object of the present invention to provide a fluffed cellulose having totally new properties that have not conventionally existed, and a cellulose fiber-containing material capable of realizing the same. The present invention relates to a cellulose fiber-containing material comprising cellulose fibers having anionic groups, wherein the yield of the cellulose fiber-containing material measured by the following measurement method is 50% by mass or more, the cellulose fiber-containing material has organic onium ions as counterions of the anionic groups, and the organic onium ions satisfy a predetermined condition.

It is an object of the present invention to provide a fluffed cellulose having totally new properties that have not conventionally existed, and a cellulose fiber-containing material capable of realizing the same. The present invention relates to a cellulose fiber-containing material comprising cellulose fibers having anionic groups, wherein the yield of the cellulose fiber-containing material measured by the following measurement method is 50% by mass or more, the cellulose fiber-containing material has organic onium ions as counterions of the anionic groups, and the organic onium ions satisfy a predetermined condition.

It is an object of the present invention to provide a resin composite that is excellent in water resistance and is capable of exerting sufficient strength even under wet conditions. The present invention relates to a resin composite comprising a resin, fibers having an ionic functional group, and a polyvalent ion. The fibers having an ionic functional group are preferably cellulose fibers having a fiber width of 1000 nm or less.

It is an object of the present invention to provide a resin composite that is excellent in water resistance and is capable of exerting sufficient strength even under wet conditions. The present invention relates to a resin composite comprising a resin, fibers having an ionic functional group, and a polyvalent ion. The fibers having an ionic functional group are preferably cellulose fibers having a fiber width of 1000 nm or less.

A method is for manufacturing cellulose microfibers in which a problem of yellowing of cellulose microfibers to be obtained was solved, and cellulose microfibers. As to a method for manufacturing cellulose microfibers, cellulose fibers are added with an additive (A) consisting of at least one of a phosphorous acid and a metal phosphite and an additive (B) consisting of at least one of urea and a urea derivative, heated and washed, then fibrillated. Also, as to cellulose microfibers, the fiber width is 1 to 1000 nm, and a part of hydroxy groups of cellulose fibers is substituted with a functional group represented by a predetermined structural formula to introduce an ester of phosphorous acid.

The present description is related to methods for derivatizing cellulose pulp, and to products obtainable using said method.

A fine cellulose fiber-containing substance that has excellent dispersibility in water and can be manufactured easily. A method is for manufacturing the fine cellulose fiber-containing substance, and a method is for manufacturing a fine cellulose fiber dispersion. A fine cellulose fiber-containing substance contains fine cellulose fibers into which a phosphite containing a cation of an inorganic substance is introduced. The ratio of the cation of the inorganic substance with respect to 1 g of the fine cellulose fibers is 0.14 mmol or more. In manufacturing the fine cellulose fiber-containing substance, a phosphite is introduced into cellulose fibers, and then the cellulose fibers are defibrated to obtain a dispersion containing fine cellulose fibers, during which an alkali metal ion-containing substance is added to the cellulose fibers, and the dispersion is concentrated. In manufacturing a fine cellulose fiber dispersion, the fine cellulose fiber-containing substance is mixed with water.

The present disclosure relates to lignocellulosic materials comprising phosphorylated lignocellulosic fibers having an ionic charge in water of about 4000 to about 7000 mmoles/kg, and processes for the preparation thereof. The process comprises reacting lignocellulosic fibers of a lignocellulosic material with a phosphate ester in the presence of urea. The present disclosure further relates to compositions comprising a phosphate ester and at least one of a defoamer and a viscosity reducer or at least one of a C1-C12 alcohol and an ester of a carboxylic acid.