Abstract: 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.

Abstract: An object is to optimize a bleaching process in a step of producing phosphorylated cellulose fibers. A pulp comprises cellulose fibers having 0.5 mmol/g or more of phosphoric acid groups or phosphoric acid group-derived substituents, when the pulp is processed into a sheet and four sheets are laminated on one another, the ISO whiteness of the laminate is 82% or more. Moreover, when the pulp is processed into a sheet and four sheets are then laminated on one another, the b* value of the obtained laminate according to the L*a*b* color system is 5.5 or less.

Abstract: It is an object of the present invention to optimize a bleaching process in a step of producing phosphorylated cellulose fibers. The present invention relates to a pulp comprising cellulose fibers having 0.5 mmol/g or more of phosphoric acid groups or phosphoric acid group-derived substituents, wherein when the pulp is processed into a sheet and four sheets are laminated on one another, the ISO whiteness of the laminate is 82% or more. Moreover, when the pulp of the present invention is processed into a sheet and four sheets are then laminated on one another, the b* value of the obtained laminate according to the L*a*b* color system is 5.5 or less.

Abstract: It is an object of the present invention to suppress agglutination of ultrafine cellulose fibers, while using the ultrafine cellulose fibers as a thickener in a cosmetic product formulation, so as to provide a uniform cosmetic. The present invention provides a cosmetic comprising the following components (A) and (B): (A) ultrafine cellulose fibers having a fiber width of 1000 nm or less; and (B) a water-soluble polymer.

Abstract: 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.

Abstract: 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.

Abstract: It is an object of the present invention to provide a method for producing ultrafine fibrous cellulose, which is capable of efficiently obtaining ultrafine fibrous cellulose having phosphoric acid groups with a high yield. The present invention relates to a method for producing fibrous cellulose having a fiber width of 1000 nm or less, comprising: a (A) of introducing phosphoric acid groups into cellulose fibers to form crosslinked structures via the phosphoric acid groups, thereby obtaining crosslinked phosphorylated cellulose fibers, a (B) of breaking some or all of the crosslinked structures to obtain crosslink-broken phosphorylated cellulose fibers, and a (C) of performing a mechanical treatment on the crosslink-broken phosphorylated cellulose fibers to obtain fibrous cellulose having a fiber width of 1000 nm or less, wherein, in the (A), crosslinked structures in an amount of 0.05 mmol/g or more and 2.

Abstract: An object of the invention is to provide a material comprising ultrafine cellulose fibers, having good dispersibility of fine particles in an aqueous medium containing ultrafine cellulose fibers. According to the invention, there is provided a material comprising ultrafine cellulose fibers, wherein the content of the ultrafine cellulose fibers is 80% by mass or more, and the haze value of a sample, which has been prepared by adding the material comprising ultrafine cellulose fibers to pure water to a solid concentration of 0.4% by mass, and stirring the mixture with a disperser under conditions of 1500 rpm and 5 minutes, is 20% or less.

Abstract: 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.

Abstract: The object is to provide a subterranean formation processing composition which has a highly stable viscosity against change in temperature and a high water stopping property. A subterranean formation processing composition comprising cellulose fibers wherein the composition contains ultrafine cellulose fibers having 0.14 to 2.5 mmol/g of a substituent is used. The substituent is preferably an anion group, particularly a phosphoric acid group. The present invention relates to various fluids which are used in well processing. The present invention relates to a method for processing a subterranean formation, for example, drilling of an exploratory well or a wildcat, an appraisal well, an exploratory well or an exploration well, a delineation well, a development well, a production well, an injection well, an observation well, and a service well; cementing; fracturing; and a method for producing petroleum resources.

Abstract: It is an object of the present invention to provide a method for producing ultrafine fibrous cellulose, which is capable of efficiently obtaining ultrafine fibrous cellulose having phosphoric acid groups with a high yield. The present invention relates to a method for producing fibrous cellulose having a fiber width of 1000 nm or less, comprising: a (A) of introducing phosphoric acid groups into cellulose fibers to form crosslinked structures via the phosphoric acid groups, thereby obtaining crosslinked phosphorylated cellulose fibers, a (B) of breaking some or all of the crosslinked structures to obtain crosslink-broken phosphorylated cellulose fibers, and a (C) of performing a mechanical treatment on the crosslink-broken phosphorylated cellulose fibers to obtain fibrous cellulose having a fiber width of 1000 nm or less, wherein, in the (A), crosslinked structures in an amount of 0.05 mmol/g or more and 2.

Abstract: An object of the invention is to provide a material or composition comprising ultrafine cellulose fibers having excellent fluidity. The invention relates to a composition comprising a particulate material comprising ultrafine cellulose fibers and water, and (B) a non-cellulose particulate material in which the water content of the composition is 2 to 94% by mass with respect to the total mass of the composition, and the content of (B) the non-cellulose particulate material is 0.1 to 12% by mass with respect to the total mass of the composition. The invention also relates to a method for producing the composition and a method for producing a material comprising ultrafine cellulose fibers.

Abstract: It is an object of the present invention to provide a method for producing ultrafine fibrous cellulose, which is capable of efficiently obtaining ultrafine fibrous cellulose having phosphoric acid groups with a high yield. The present invention relates to a method for producing fibrous cellulose having a fiber width of 1000 nm or less, comprising: a (A) of introducing phosphoric acid groups into cellulose fibers to form crosslinked structures via the phosphoric acid groups, thereby obtaining crosslinked phosphorylated cellulose fibers, a (B) of breaking some or all of the crosslinked structures to obtain crosslink-broken phosphorylated cellulose fibers, and a (C) of performing a mechanical treatment on the crosslink-broken phosphorylated cellulose fibers to obtain fibrous cellulose having a fiber width of 1000 nm or less, wherein, in the (A), crosslinked structures in an amount of 0.05 mmol/g or more and 2.

Abstract: An object is to provide a dispersion of ultrafine cellulose fibers having a high thickening effect and a gelling function. There is provided a subterranean formation processing composition comprising ultrafine cellulose fibers, which has a haze value of 1.0% to 50%, when the composition is suspended in water such that the solid concentration of cellulose fibers is 0.2% by mass. The composition of the present invention can be used as an additive to the fluid at the time of the processing of subterranean formation, especially the processing of the well. The present invention provides also various fluids which are used in well processing.

Abstract: It is an object of the present invention to provide a method for producing ultrafine fibrous cellulose, which is capable of efficiently obtaining ultrafine fibrous cellulose having phosphoric acid groups with a high yield. The present invention relates to a method for producing fibrous cellulose having a fiber width of 1000 nm or less, comprising: a (A) of introducing phosphoric acid groups into cellulose fibers to form crosslinked structures via the phosphoric acid groups, thereby obtaining crosslinked phosphorylated cellulose fibers, a (B) of breaking some or all of the crosslinked structures to obtain crosslink-broken phosphorylated cellulose fibers, and a (C) of performing a mechanical treatment on the crosslink-broken phosphorylated cellulose fibers to obtain fibrous cellulose having a fiber width of 1000 nm or less, wherein, in the (A), crosslinked structures in an amount of 0.05 mmol/g or more and 2.

Abstract: An object of the invention is to provide a material or composition comprising ultrafine cellulose fibers having excellent fluidity. The invention relates to a composition comprising a particulate material comprising ultrafine cellulose fibers and water, and (B) a non-cellulose particulate material in which the water content of the composition is 2 to 94% by mass with respect to the total mass of the composition, and the content of (B) the non-cellulose particulate material is 0.1 to 12% by mass with respect to the total mass of the composition. The invention also relates to a method for producing the composition and a method for producing a material comprising ultrafine cellulose fibers.

Abstract: It is an object of the present invention to suppress agglutination of ultrafine cellulose fibers, while using the ultrafine cellulose fibers as a thickener in a cosmetic product formulation, so as to provide a uniform cosmetic. The present invention provides a cosmetic comprising the following components (A) and (B): (A) ultrafine cellulose fibers having a fiber width of 1000 nm or less; and (B) a water-soluble polymer.

Abstract: An object of the invention is to provide a material comprising ultrafine cellulose fibers, having good dispersibility of fine particles in an aqueous medium containing ultrafine cellulose fibers. According to the invention, there is provided a material comprising ultrafine cellulose fibers, wherein the content of the ultrafine cellulose fibers is 80% by mass or more, and the haze value of a sample, which has been prepared by adding the material comprising ultrafine cellulose fibers to pure water to a solid concentration of 0.4% by mass, and stirring the mixture with a disperser under conditions of 1500 rpm and 5 minutes, is 20% or less.

Abstract: An object is to provide a dispersion of ultrafine cellulose fibers having a high thickening effect and a gelling function. There is provided a subterranean formation processing composition comprising ultrafine cellulose fibers, which has a haze value of 1.0% to 50%, when the composition is suspended in water such that the solid concentration of cellulose fibers is 0.2% by mass. The composition of the present invention can be used as an additive to the fluid at the time of the processing of subterranean formation, especially the processing of the well. The present invention provides also various fluids which are used in well processing.

Abstract: 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.