An object of the present invention is to provide a salt water thickener that uniformly (favorably) disperses ultrafine cellulose fibers even in a liquid containing a salt (electrolyte). The salt water thickener comprises ultrafine cellulose fibers and a water-soluble polymer and can thereby uniformly disperse the ultrafine cellulose fibers even in a liquid containing a salt. The salt water thickener of the present invention is uniformly dispersed even in a liquid containing a salt and therefore exerts a high viscosity. The salt water thickener of the present invention can also be used as an additive for a fluid. The salt water thickener of the present invention can be used for purposes, for example, subterranean formation processing.

An object of the present invention is to provide a salt water thickener that uniformly (favorably) disperses ultrafine cellulose fibers even in a liquid containing a salt (electrolyte). The salt water thickener comprises ultrafine cellulose fibers and a water-soluble polymer and can thereby uniformly disperse the ultrafine cellulose fibers even in a liquid containing a salt. The salt water thickener of the present invention is uniformly dispersed even in a liquid containing a salt and therefore exerts a high viscosity. The salt water thickener of the present invention can also be used as an additive for a fluid. The salt water thickener of the present invention can be used for purposes, for example, subterranean formation processing.

A fine cellulose fiber in which when the fine cellulose fiber is formed into a dispersion, the dispersion has very high light transmittance and viscosity, and a method for producing the fine cellulose fiber.

The fine cellulose fiber has a fiber width of 1 to 200 nm. A part of hydroxy groups of the cellulose fiber are substituted with a predetermine functional group to introduce an ester of phosphorus-oxo acid, and the introduction amount of the functional group is more than 2.0 mmol per 1 g of the cellulose fiber. For producing the fine cellulose fiber, to cellulose fiber is added a solution having a pH of less than 3.0 and including an additive (A) containing at least one of a phosphorus-oxo acid and a phosphorus-oxo acid metal salt and an additive (B) containing at least one of urea and a urea derivative, and the mixture is heated to perform fibrillation.

A fine cellulose fiber in which when the fine cellulose fiber is formed into a dispersion, the dispersion has very high light transmittance and viscosity, and a method for producing the fine cellulose fiber.

The fine cellulose fiber has a fiber width of 1 to 200 nm. A part of hydroxy groups of the cellulose fiber are substituted with a predetermine functional group to introduce an ester of phosphorus-oxo acid, and the introduction amount of the functional group is more than 2.0 mmol per 1 g of the cellulose fiber. For producing the fine cellulose fiber, to cellulose fiber is added a solution having a pH of less than 3.0 and including an additive (A) containing at least one of a phosphorus-oxo acid and a phosphorus-oxo acid metal salt and an additive (B) containing at least one of urea and a urea derivative, and the mixture is heated to perform fibrillation.

Methods of preparing a lignocellulosic biomass-based thermoplastic composition are described. In some embodiments, the method comprises: (a) preparing a mixture of solids comprising lignocellulosic biomass, a meltable solvent and a polyester; and (b) melt-compounding said mixture of solids; thereby preparing a lignocellulosic biomass-based thermoplastic composition. Fibers produced by the methods are also described, as are yarns and fabrics comprising the fibers.

Methods of preparing a lignocellulosic biomass-based thermoplastic composition are described. In some embodiments, the method comprises: (a) preparing a mixture of solids comprising lignocellulosic biomass, a meltable solvent and a polyester; and (b) melt-compounding said mixture of solids; thereby preparing a lignocellulosic biomass-based thermoplastic composition. Fibers produced by the methods are also described, as are yarns and fabrics comprising the fibers.

High permeability curly fibers with enhanced fiber strength are produced by mercerizing cellulosic fibers. The fibers have relatively high values for curl, kink level, wet tensile strength, and bulk density when compared with current fibers. The disclosed fibers can be used in a wide range of applications including paper products such as filters.

High permeability curly fibers with enhanced fiber strength are produced by mercerizing cellulosic fibers. The fibers have relatively high values for curl, kink level, wet tensile strength, and bulk density when compared with current fibers. The disclosed fibers can be used in a wide range of applications including paper products such as filters.

Objects of the present invention are to provide a phosphoric acid-esterified fine cellulose fiber of which slurry shows superior transparency, and to provide a method for producing a phosphorylated fine cellulose fiber showing superior transparency with good efficiency and high yield. According to the present invention, there is provided a phosphoric acid-esterified fine cellulose fiber, of which 0.2 mass % aqueous dispersion shows a solution haze of 15% or lower.

Objects of the present invention are to provide a phosphoric acid-esterified fine cellulose fiber of which slurry shows superior transparency, and to provide a method for producing a phosphorylated fine cellulose fiber showing superior transparency with good efficiency and high yield. According to the present invention, there is provided a phosphoric acid-esterified fine cellulose fiber, of which 0.2 mass % aqueous dispersion shows a solution haze of 15% or lower.