A buffer material of the present disclosure is a material including cellulose fibers and a binding material that binds the cellulose fibers, in which the binding material is a natural component and a proportion of the binding material in the buffer material is 10.0% by mass or greater and 30.0% by mass or less. It is preferable that the buffer material of the present disclosure have a thickness of 1.0 mm or greater and 100 mm or less and that the buffer material have a density of 0.02 g/cm.sup.3 or greater and 0.20 g/cm.sup.3 or less. It is preferable that the binding material contain a shellac resin. It is preferable that a content of lignin in the cellulose fibers be 5.0% by mass or less.

Grafted, crosslinked cellulosic materials include cellulose fibers and polymer chains composed of at least one monoethylenically unsaturated acid group-containing monomer (such as acrylic acid) grafted thereto, in which one or more of said cellulose fibers and said polymer chains are crosslinked (such as by intra-fiber chain-to-chain crosslinks). Some of such materials are characterized by a wet bulk of about 10.0-17.0 cm3/g, an IPRP value of about 1000 to 7700 cm2/MPa.Math.sec, and/or a MAP value of about 7.0 to 38 cm H2O. Methods for producing such materials may include grafting polymer chains from a cellulosic substrate, followed by treating the grafted material with a crosslinking agent adapted to effect crosslinking of one or more of the cellulosic substrate or the polymer chains. Example crosslinking mechanisms include esterfication reactions, ionic reactions, and radical reactions, and example crosslinking agents include pentaerythritol, homopolymers of the graft species monomer, and hyperbranched polymers.

There is provided a method of producing a sheet having a density of 0.6-1.3 g/cm.sup.3 measured according to ISO 534:2011, the sheet comprising chemically modified cellulose fibres, wherein the method comprises: a. providing chemically modified cellulose fibres, wherein charge density measured according to SCAN-CM 65:02 of the chemically modified cellulose fibres is 1200-2400 μeq/g; b. forming a fibre web by dewatering a slurry comprising the chemically modified cellulose fibres on a forming wire; and c. drying the fibre web to obtain the sheet, with the proviso that no carboxymethyl cellulose (CMC) is added to the chemically modified cellulose fibres during or prior to step b.

Provided is a polyamide resin molded article having high mechanical properties and dimensional accuracy as well as low friction coefficient, low wear, and/or low abrasion property. The present invention provides a polyamide resin molded article composed of a polyamide resin composition including (A) a polyamide resin, (B) chemically modified cellulose microfibers having a weight average molecular weight (Mw) of 100,000 or more, a ratio (Mw/Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of 6 or less, an alkali-soluble polysaccharides average content of 12 mass percent or less, and a degree of crystallization of 60% or more, and (C) a dispersant having a melting point of 80° C. or less and a number average molecular weight of 1000-50,000, wherein the melting point (Tm) and the crystallization temperature (Tc) of the polyamide resin molded article satisfy formula (1): Tm−Tc≥30° C. . . . (1).

[Object] An object is to provide a sulfonated fine cellulose fiber having excellent transparency a sulfonated pulp fiber suitable for the sulfonated fine cellulose fiber, a method for producing these fibers, and a derivative pulp containing the sulfonated pulp fiber.

[Means for achieving the object] The sulfonated pulp fiber of the present invention is a pulp fiber comprising a plurality of cellulose fibers, wherein a part of hydroxyl groups of the cellulose fibers of the pulp fiber is substituted with sulfo groups, an introduction amount of sulfur attributable to the sulfo groups is adjusted to be higher than 0.42 mmol/g while maintaining a fiber shape, and a water retention value of the pulp fiber is adjusted to 150% or more. Since the sulfonated pulp fiber has a predetermined water retaining property or more while maintaining the fiber shape, the degree of flexibility in handling can be improved.

The present invention provides a novel method for producing carboxymethylated cellulose, the method making it possible to economically obtain a high-transparency cellulose nanofiber dispersion. In the carboxymethylation of cellulose, mercerization is carried out in a solvent comprising mainly water, and then carboxymethylation is carried out in a mixed solvent of water and an organic solvent. A nanofiber dispersion of high-transparency carboxymethylated cellulose can be obtained by defibrating the resulting carboxymethylated cellulose.

Grafted, crosslinked cellulosic materials include cellulose fibers and polymer chains composed of at least one monoethylenically unsaturated acid group-containing monomer (such as acrylic acid) grafted thereto, in which one or more of said cellulose fibers and said polymer chains are crosslinked (such as by intra-fiber chain-to-chain crosslinks). Some of such materials are characterized by a wet bulk of about 10.0-17.0 cm3/g, an IPRP value of about 1000 to 7700 cm2/MPa.Math.sec, and/or a MAP value of about 7.0 to 38 cm H2O. Methods for producing such materials may include grafting polymer chains from a cellulosic substrate, followed by treating the grafted material with a crosslinking agent adapted to effect crosslinking of one or more of the cellulosic substrate or the polymer chains. Example crosslinking mechanisms include esterfication reactions, ionic reactions, and radical reactions, and example crosslinking agents include pentaerythritol, homopolymers of the graft species monomer, and hyperbranched polymers.

The present invention provides a method for the production of chemically derivatized nanocellulose, comprising the step of a. contacting a precursor cellulosic material with a chemically derivatizing composition to form a liquid reaction mixture, and b. chemically reacting the formed liquid reaction mixture, and c. subjecting the formed liquid reaction mixture to microfluidisation, wherein the steps b. and c. are carried out simultaneously.

According to an example aspect of the present invention, there is provided a process for the conversion of cellulosic waste material into a recycled cellulose product comprising the steps of cooking the waste material in a cooking liquor to remove lignin from the waste material and provide a delignified pulp, dissolving the delignified pulp in an ionic liquid to provide a spinning dope suitable for dry jet-wet spinning in an ionic liquid solution, and subjecting the spinning dope to a further processing step to provide a recycled cellulose product, said further step selected from the group of spinning cellulose fibers for use in textiles from the solution, extruding a film product for use in packaging, regenerating the dope as a hydrogel and regenerating the dope as an aerogel.

A method for manufacturing a fibrous cellulose having a high resin reinforcing effect and a method for manufacturing a fibrous cellulose composite resin having high strength. A method for manufacturing a fibrous cellulose includes: a step of subjecting a cellulose raw material and at least one of urea and a derivative of urea to a heat treatment to replace a part or all of hydroxyl groups of the cellulose raw material with carbamate groups; and a step of defibrating the cellulose raw material within a range in which an average fiber width is 0.1 μm or more. The heat treatment is performed under a condition that organic acid ions are added in an amount of 0.001 mmol or more with respect to 1 g of the urea and the derivative of urea. In addition, a fibrous cellulose thus obtained and a resin are kneaded to manufacture a fibrous cellulose composite resin.