Abstract: Provided is a water-absorbing agent that causes no or little fluctuation of feed rate when fed with use of a feeder. A water-absorbing agent containing a water-absorbing resin as a main component, the water-absorbing agent satisfying the following (a) and (b): (a) K-index is 70 or more; and (b) Moisture absorption blocking ratio, after 30 minutes of standing at a temperature of 25° C. and a relative humidity of 80% RH, is 70 weight % or less, the K-index being defined by the following equation: K-index=100?(?438+3.6×angle of repose+3.5×angle of difference+7.9×compressibility rate+290×bulk density (EDANA method)).

Abstract: Provided is a water-absorbing agent that causes no or little fluctuation of feed rate when fed with use of a feeder. A water-absorbing agent containing a water-absorbing resin as a main component, the water-absorbing agent satisfying the following (a) and (b): (a) K-index is 70 or more; and (b) Moisture absorption blocking ratio, after 30 minutes of standing at a temperature of 25° C. and a relative humidity of 80% RH, is 70 weight % or less, the K-index being defined by the following equation: K-index=100?(?438+3.6×angle of repose+3.5×angle of difference+7.9×compressibility rate+290×bulk density (EDANA method)).

Abstract: An injection molding device includes: a lower die that supports a rotor core; an intermediate die including a magnetizing mechanism; and an upper die including an injection die having a gate formed therein through which a molten bonded-magnet material supplied from a supply source is injected into a magnet insertion hole in the rotor core. The injection die has a cylindrical protruding portion at an end surface of which the gate is open. In the protruding portion, a magnetic-flux applying member containing ferromagnetic material is embedded with its side surface exposed at an outer peripheral surface of the protruding portion. The magnetizing mechanism is formed in an annular shape that can accommodate, inside its inner periphery, the rotor core and a distal end portion of the protruding portion by disposing yokes and permanent magnets alternately in the circumferential direction. Magnetic-path surfaces of the yokes radially face the side surface.

Abstract: An object of the present invention is to provide a method for producing water absorbent resin powder in which permeability potential (SFC) is improved while a water absorbing rate (FSR) is being kept. The method is a method for producing water absorbent polyacrylic acid (salt) resin powder including the steps of: (i) polymerizing an acrylic acid (salt) monomer aqueous solution; (ii) during or after the step of (i), performing gel grinding of a hydrogel crosslinked polymer obtained by the polymerization, wherein the hydrogel crosslinked polymer has resin solid content of 10 wt % to 80 wt %, and the gel grinding is carried out with gel grinding energy (GGE) of 18 [J/g] to 60 [J/g]; (iii) drying a particulate hydrogel crosslinked polymer obtained by the gel grinding, wherein the drying is performed at 150° C. to 250° C.; and (iv) carrying out a surface treatment to the particulate hydrogel crosslinked polymer thus dried.

Abstract: An object of the present invention is to provide a water absorbent resin which attains high liquid permeability and water absorbing speed, and which does not have problems of coloring and odor. The water absorbent resin includes: (A) a water absorbent resin particle having a carboxyl group; (B) a covalent surface crosslinking agent in which the number of carbons is not more than 10; (C) 0.001 mass % to 0.2 mass % of a water-soluble or water-dispersible polymer whose Log P is not less than 1.0; and (D) 0.001 mass % to 1 mass % of a water-soluble polyvalent cation. The water absorbent resin has not less than 20 g/g of a fixed height absorption (FHA) at a height of 20 cm.

Abstract: An orientation magnetization device includes plural orientation magnetization yokes and plural orientation magnetization magnets, and molds field magnets while a rotor core is disposed in a magnetic circuit that is formed by assembling the orientation magnetization yokes and the orientation magnetization magnets into an annular shape. When the rotor core is disposed in the magnetic circuit, protruding portions are disposed at portions of the respective orientation magnetization yokes facing the rotor core. Auxiliary magnets are disposed in gaps between the respective orientation magnetization magnets and the rotor core, on opposite sides of each protruding portion in a circumferential direction of the orientation magnetization device. Each protruding portion and each auxiliary magnet extend in an axial direction of the orientation magnetization device, and are skewed with respect to the axial direction of the orientation magnetization device.

Abstract: An interior permanent magnet rotor includes a cylindrical rotor core having an axial hole extending in an axial direction, and a resin magnet that is formed to fill the axial hole by injection molding and that has a pair of axial end faces. The resin magnet includes a linear portion that has a linear shape in section perpendicular to the axial direction of the rotor core. The linear portion has a first end and a second end located closer to an outer periphery of the rotor core than the first end is. A gate mark is located on the second end of the linear portion on at least one of the axial end faces of the resin magnet.

Abstract: An injection molding device includes: a lower die that supports a rotor core; an intermediate die including a magnetizing mechanism; and an upper die including an injection die having a gate formed therein through which a molten bonded-magnet material supplied from a supply source is injected into a magnet insertion hole in the rotor core. The injection die has a cylindrical protruding portion at an end surface of which the gate is open. In the protruding portion, a magnetic-flux applying member containing ferromagnetic material is embedded with its side surface exposed at an outer peripheral surface of the protruding portion. The magnetizing mechanism is formed in an annular shape that can accommodate, inside its inner periphery, the rotor core and a distal end portion of the protruding portion by disposing yokes and permanent magnets alternately in the circumferential direction. Magnetic-path surfaces of the yokes radially face the side surface.

Abstract: An orientation magnetization device includes plural orientation magnetization yokes and plural orientation magnetization magnets, and molds field magnets while a rotor core is disposed in a magnetic circuit that is formed by assembling the orientation magnetization yokes and the orientation magnetization magnets into an annular shape. When the rotor core is disposed in the magnetic circuit, protruding portions are disposed at portions of the respective orientation magnetization yokes facing the rotor core. Auxiliary magnets are disposed in gaps between the respective orientation magnetization magnets and the rotor core, on opposite sides of each protruding portion in a circumferential direction of the orientation magnetization device. Each protruding portion and each auxiliary magnet extend in an axial direction of the orientation magnetization device, and are skewed with respect to the axial direction of the orientation magnetization device.

Abstract: An object of the present invention is to provide a method for producing water absorbent resin powder in which permeability potential (SFC) is improved while a water absorbing rate (FSR) is being kept. The method is a method for producing water absorbent polyacrylic acid (salt) resin powder including the steps of: (i) polymerizing an acrylic acid (salt) monomer aqueous solution; (ii) during or after the step of (i), performing gel grinding of a hydrogel crosslinked polymer obtained by the polymerization, wherein the hydrogel crosslinked polymer has resin solid content of 10 wt % to 80 wt %, and the gel grinding is carried out with gel grinding energy (GGE) of 18 [J/g] to 60 [J/g]; (iii) drying a particulate hydrogel crosslinked polymer obtained by the gel grinding, wherein the drying is performed at 150° C. to 250° C.; and (iv) carrying out a surface treatment to the particulate hydrogel crosslinked polymer thus dried.

Abstract: An object of the present invention is to provide a method for producing water absorbent resin powder in which permeability potential (SFC) is improved while a water absorbing rate (FSR) is being kept. The method is a method for producing water absorbent polyacrylic acid (salt) resin powder including the steps of: (i) polymerizing an acrylic acid (salt) monomer aqueous solution; (ii) during or after the step of (i), performing gel grinding of a hydrogel crosslinked polymer obtained by the polymerization, wherein the hydrogel crosslinked polymer has resin solid content of 10 wt % to 80 wt %, and the gel grinding is carried out with gel grinding energy (GGE) of 18 [J/g] to 60 [J/g]; (iii) drying a particulate hydrogel crosslinked polymer obtained by the gel grinding, wherein the drying is performed at 150° C. to 250° C.; and (iv) carrying out a surface treatment to the particulate hydrogel crosslinked polymer thus dried.

Abstract: An interior permanent magnet rotor includes a cylindrical rotor core having an axial hole extending in an axial direction, and a resin magnet that is formed to fill the axial hole by injection molding and that has a pair of axial end faces. The resin magnet includes a linear portion that has a linear shape in section perpendicular to the axial direction of the rotor core. The linear portion has a first end and a second end located closer to an outer periphery of the rotor core than the first end is. A gate mark is located on the second end of the linear portion on at least one of the axial end faces of the resin magnet.

Abstract: An object of the present invention is to provide a water absorbent resin which attains high liquid permeability and water absorbing speed, and which does not have problems of coloring and odor. The water absorbent resin includes: (A) a water absorbent resin particle having a carboxyl group; (B) a covalent surface crosslinking agent in which the number of carbons is not more than 10; (C) 0.001 mass % to 0.2 mass % of a water-soluble or water-dispersible polymer whose Log P is not less than 1.0; and (D) 0.001 mass % to 1 mass % of a water-soluble polyvalent cation. The water absorbent resin has not less than 20 g/g of a fixed height absorption (FHA) at a height of 20 cm.

Abstract: The purpose of the present invention is to provide a method for producing a water absorbent resin having improved physical properties, particularly, improved saline flow conductivity (SFC) and less amount of fine powder.

Abstract: The purpose of the present invention is to provide a method for producing a water absorbent resin having improved physical properties, particularly, improved saline flow conductivity (SFC) and less amount of fine powder.

Abstract: An object of the present invention is to provide a method for producing water absorbent resin powder in which permeability potential (SFC) is improved while a water absorbing rate (FSR) is being kept. The method is a method for producing water absorbent polyacrylic acid (salt) resin powder including the steps of: (i) polymerizing an acrylic acid (salt) monomer aqueous solution; (ii) during or after the step of (i), performing gel grinding of a hydrogel crosslinked polymer obtained by the polymerization, wherein the hydrogel crosslinked polymer has resin solid content of 10 wt % to 80 wt %, and the gel grinding is carried out with gel grinding energy (GGE) of 18 [J/g] to 60 [J/g]; (iii) drying a particulate hydrogel crosslinked polymer obtained by the gel grinding, wherein the drying is performed at 150° C. to 250° C.; and (iv) carrying out a surface treatment to the particulate hydrogel crosslinked polymer thus dried.