To provide a disposable diaper enabling reduction in re-wet amount and having an excellent speed of incorporating liquid regardless of concentration and configuration of a water-absorbing agent in an absorbent material.

A water-absorbing agent having excellent Gel Capillary Absorption (GCA) and Free Gel Bed Permeability (FGBP) is obtained by crushing a crosslinked hydrogel polymer obtained in a polymerization step to have a specific weight average particle diameter while fluid retention capacity and a surface tension of a water-absorbing agent are adjusted in a specific range, drying the crushed crosslinked hydrogel polymer, and then adding a liquid permeability enhancer thereto during surface crosslinking or after surface crosslinking.

To provide a disposable diaper enabling reduction in re-wet amount and having an excellent speed of incorporating liquid regardless of concentration and configuration of a water-absorbing agent in an absorbent material.

A water-absorbing agent having excellent Gel Capillary Absorption (GCA) and Free Gel Bed Permeability (FGBP) is obtained by crushing a crosslinked hydrogel polymer obtained in a polymerization step to have a specific weight average particle diameter while fluid retention capacity and a surface tension of a water-absorbing agent are adjusted in a specific range, drying the crushed crosslinked hydrogel polymer, and then adding a liquid permeability enhancer thereto during surface crosslinking or after surface crosslinking.

It is an object to provide a water-absorbing resin that while maintaining water-absorbing resin physical properties such as water absorption performance, has a sufficiently reduced odor produced during swelling. The object is attained by causing the water-absorbing resin to be a water-absorbing resin which is a surface-crosslinked water-absorbing resin, the water-absorbing resin having a volatile component concentration of 3.5 ppm or less as measured when the water-absorbing resin is caused to stand still for 15 minutes under a condition that the water-absorbing resin has a swelling capacity of 1.0-fold.

The object of the present invention is to provide a production method which makes it possible to obtain a PHA with a simple operation. The object can be attained by providing a method for producing a polyhydroxyalkanoate, the method including the steps of: (a) preparing an aqueous polyhydroxyalkanoate suspension having a pH of not more than 7; and (b) heating the aqueous polyhydroxyalkanoate suspension, prepared in the step (a), at a temperature set at 80° C. to 300° C. in a twin screw extruder so as to aggregate a polyhydroxyalkanoate.

A nonlimiting example method for synthesizing a pigment-pendent polyamide (PP-polyamide) may comprise: functionalizing metal oxide particles bound to a pigment particle with a compound having an epoxy to produce a surface treated pigment having a pendent epoxy; and reacting the pendent epoxy with a polyamide to yield the PP-polyamide. Another nonlimiting example method for synthesizing a PP-polyamide may comprise: functionalizing metal oxide particles bound to a pigment particle with a silica particle having a carboxylic acid surface treatment to produce a surface treated pigment having a pendent carboxylic acid; converting the pendent carboxylic acid to a pendent acid chloride; and reacting the pendent acid chloride with a polyamide to yield the PP-polyamide. Said PP-polyamide may be useful in producing objects by methods that include melt extrusion, injection molding, compression molding, melt spinning, melt emulsification, spray drying, cryogenic milling, freeze drying polymer dispersions, and precipitation of polymer dispersions.

A hydrophilic silicone particle containing a surfactant fixed by a chemical bond formed by radical polymerization to a surface of a silicone particle having a volume average particle size of 0.1 to 100 μm and a method for producing the hydrophilic silicone particle, the method including fixing a hydrophilic group derived from a component (B) to a surface of a silicone particle by subjecting an emulsion to radical polymerization, the emulsion containing: (A) 100 parts by mass of an organopolysiloxane having a radical polymerization reactive group; (B) 0.5 to 50 parts by mass of a surfactant having a radical polymerization reactive group; (C) 0.1 to 5 parts by mass of a radical generator; and (D) 10 to 1000 parts by mass of water. A silicone particle may be readily dispersed in an aqueous material without the additional use of a dispersant (typically, a surfactant) and has a hydrophilic group.

A silicone particle containing: a dialkylsiloxane unit represented by the following general formula (1), R.sup.4.sub.2SiO.sub.2/2 (1), where, in the formula (1), R.sup.4s each independently represent a monovalent hydrocarbon group having 1 to 6 carbon atoms; and a poly(alkyleneoxyalkyl)methylsiloxane unit represented by the following general formula (2), where, in the formula (2), R.sup.1s each independently represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, R.sup.2s each independently represent a divalent aliphatic group having 1 to 6 carbon atoms, and “n” is a number that satisfies 1≤n≤20, where the silicone particle has an oxyalkylene group in a surface thereof. A silicone particle may be readily dispersed in an aqueous material without the use of a dispersant or a surfactant, the silicone particle having a hydrophilic group.

##STR00001##

A silicone particle containing: a dialkylsiloxane unit represented by the following general formula (1), R.sup.4.sub.2SiO.sub.2/2 (1), where, in the formula (1), R.sup.4s each independently represent a monovalent hydrocarbon group having 1 to 6 carbon atoms; and a poly(alkyleneoxyalkyl)methylsiloxane unit represented by the following general formula (2), where, in the formula (2), R.sup.1s each independently represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, R.sup.2s each independently represent a divalent aliphatic group having 1 to 6 carbon atoms, and “n” is a number that satisfies 1≤n≤20, where the silicone particle has an oxyalkylene group in a surface thereof. A silicone particle may be readily dispersed in an aqueous material without the use of a dispersant or a surfactant, the silicone particle having a hydrophilic group.

##STR00001##

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.

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.